Mill head for a bone mill, the mill head having one or more containment rings that prevent unwanted discharge of the contents of the bone mill

Patent metadata

Field	Value
Publication number	US-9655631-B2
Application number	US-201414282460-A
Country	US
Kind code	B2
Filing date	May 20, 2014
Priority date	Nov 7, 2007
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A mill head for replaceable attachment to a base so as to collectively form a bone mill. The mill head includes: a first opening in which bone stock is introduced into the head; a cutting device that converts the bone stock into bone chips; a second opening through which the bone chips are discharged; and a third opening through which a motor integral with the base is attached to the cutting device. Internal to the mill head are containment rings. The containment rings prevent the discharge of material through the third opening. The containment rings are services the internal component of the mill head on which the cutting device rests.

First claim

What is claimed is:

1. A mill head for use with a bone mill, said mill head including:
a shell, said shell having: opposed and spaced apart top and bottom sections; a centrally located longitudinal axis that extends top-to-bottom through said shell; a first opening in the shell top section; a second opening in the shell bottom section; and a third opening in the shell bottom section, the third opening being closer to the longitudinal axis of the shell than the second opening;
an impingement surface integral with the top section of said shell;
a cutting device movably disposed in said shell between the impingement surface and shell bottom section, said cutting device including: at least one cutting feature located between the shell first and second openings, said cutting feature configured to press bone stock introduced into the shell first opening against the impingement surface so that the bone stock is converted to bone chips that are discharged through the shell second opening;
a coupling feature integral with said cutting device that is accessible through the shell third opening, said coupling feature configured to engage a spindle of the bone mill so that the rotation of the spindle results in the like rotation of the said cutting device; and
a first ring that extends upwardly from an inner surface of the shell bottom section around the third opening so as to separate the second and third openings and prevent the discharge of bone chips through the third opening.

2. The mill head of claim 1 , wherein said impingement surface is part of an impingement plate that is separate from the shell top section and that is attached to the shell top section.

3. The mill head of claim 1 , wherein said cutting device is formed with at least one opening that is accessible through the shell third opening, said cutting device at least one opening being said coupling feature integral with said cutting device.

4. The mill head of claim 1 , wherein:
said cutting device is mounted in said shell to both rotate in said shell and to at least one of move along either the axis of rotation or move along or around another axis; and
an alignment feature is attached to said cutting device for engaging a complementary alignment feature associated with the spindle so that the engagement of the alignment features positions said cutting device relative to the spindle so that the spindle can engage said coupling feature.

5. The mill head of claim 4 , wherein said coupling feature attached to said cutting device and said alignment feature attached to said cutting device are different features.

6. The mill head of claim 1 , wherein a catch tray is removably attached to said shell so as to be located below the shell second opening.

7. The mill head of claim 1 , wherein:
said cutting device is formed to have: a top surface that is directed to the shell top section; a bottom surface that is directed to the shell bottom section; and a thickness between the top and bottom surfaces;
there is a vertical gap in said shell between said first ring and an opposed adjacent surface of the shell top section, the gap having a distance thereacross;
said cutting device is disposed in said shell so as to be seated on said first ring; and
the thickness of said cutting device is less than the distance across the gap in said shell.

8. A mill head for use with a bone mill, said mill head including:
a shell, said shell having: opposed and spaced apart top and bottom sections; a centrally located longitudinal axis that extends top-to-bottom through said shell; a first opening in the shell top section; a second opening in the shell bottom section; and a third opening in the shell bottom section, the third opening being closer to the longitudinal axis of the shell than the second opening;
a first ring that extends downwardly from the shell top section so as to extend around the shell third opening;
a cutting device movably disposed in said shell between the shell top shell top section and the shell bottom section, said cutting device including at least one cutting feature located radially outwardly of the first ring and between the shell first and second openings that is configured to convert bone stock introduced into the shell first opening into bone chips that are discharged through the shell second opening;
a coupling feature integral with said cutting device that is accessible through the shell third opening, said coupling feature configured to engage a spindle of the bone mill so that the rotation of the spindle results in the like rotation of the said cutting device; and
a second ring that extends upwardly from an inner surface of the shell bottom section around the third opening so as to separate the second and third openings and prevent the discharge of bone chips through the third opening.

9. The mill head of claim 8 , wherein
a third ring extends upwardly from the shell bottom section, said third ring being spaced away and located radially outwardly from the second ring;
said cutting device is dimensioned to seat over said second ring and said third ring; and
said at least one cutting feature is disposed on said cutting device to be located between said second ring and said third ring.

10. The mill head of claim 8 , wherein:
the shell top section has an impingent surface; and
said cutting device at least one cutting feature is configured to press bone stock against the shell top section impingement surface so as to cause the shearing of bone stock against the impingement surface into bone chips.

11. The mill head of claim 8 , wherein:
said cutting device is mounted in said shell to both rotate in said shell and to at least one of move along either the axis of rotation or move along or around another axis; and
an alignment feature is attached to said cutting device for engaging a complementary alignment feature associated with the spindle so that the engagement of the alignment features positions said cutting device relative to the spindle so that the spindle can engage said coupling feature.

12. The mill head of claim 11 , wherein said coupling feature attached to said cutting device and said alignment feature attached to said cutting device are different features.

13. The mill head of claim 8 , wherein:
in said shell between said first ring and said second ring there is a gap between said rings, the gap having a vertical distance; and
said cutting device has: a top surface located adjacent said first ring; a bottom surface located adjacent said second ring; and a thickness between the top and bottom surfaces, the thickness being less than the vertical distance of the gap between said rings.

14. The mill head of claim 8 , wherein said shell is further formed so that said first ring at least partially overlaps said second ring.

15. The mill head of claim 8 , wherein a catch tray is removably attached to said shell so as to be located below the shell second opening.

16. A mill head for use with a bone mill, said mill head including:
a shell, said shell having: opposed and spaced apart top and bottom sections; a centrally located longitudinal axis that extends top-to-bottom through said shell; a first opening in the shell top section; a second opening in the shell bottom section; and a third opening in the shell bottom section, the third opening being closer to the longitudinal axis of the shell than the second opening;
a first ring that extends upwardly from the shell bottom section and that is located around the shell third opening so as to be between the shell second and third openings;
a second ring that extends

Assignees

• Stryker Corp

Inventors

• Peterson Michael
• Kalinka Gary
• Burmeister Richard

Classifications

• A61F2002/4645

  Devices for grinding or milling bone material · CPC title

• A61F2002/4646

  Devices for cleaning bone graft · CPC title

• A61B2017/1602

  Mills · CPC title

• A61F2/4644

  Preparation of bone graft, bone plugs or bone dowels, e.g. grinding or milling bone material (bone material A61F2/28; disintegrating or milling devices B02C) · CPC title

• A61B17/1615 Primary

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