Bone mill including a base and a mill head separate from the base, the mill head including a moveable catch tray

• US 8,002,774 B2
• Filed: 11/07/2007
• Issued: 08/23/2011
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Sy, Ben J., Diehl, Eric K., Burmeister, Richard Frederick III, Kalinka, Gary T., Peterson, Michael J.
• Primary Examiner(s): Barrett; Thomas C
• Assistant Examiner(s): Bates; David W
• Application Number:
  US11/936,448
• Publication Number:
  US 20090118735A1
• Time in Patent Office: 1,385 Days
• Field of Search: 606/79, 606/84, 606/85, D73/78, D73/84, 241/92
• US Class Current: 606/79
• CPC Class Codes: A61B 17/1615 Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material
• CPC Class Codes: A61B 2017/1602 Mills
• CPC Class Codes: A61F 2/4644 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 Class Codes: A61F 2002/4645 Devices for grinding or milling bone material
• CPC Class Codes: A61F 2002/4646 Devices for cleaning bone graft
• CPC Class Codes: B02C 18/16 Details
• CPC Class Codes: B02C 18/22 Feed or discharge means
• CPC Class Codes: B02C 18/24 Drives

Abstract

A bone mill including a base and a mill head that is removably attached to the base. A cutting disc is rotatably disposed in the mill head. When the mill head is attached to base, the cutting disc is rotated by a motor internal to the base. A plunger mounted to the mill head urges the bone against the cutting disc. The cutting disc and an impingement plate internal to the mill head shear the bone into chips. The chips are discharged from an opening in the mill head into a catch tray removably attached to the mill head.

Claims

1. A bone mill, said bone mill including:

a base;

a motor disposed in said base;

a motor coupling feature connected to said motor; and

a mill head, said mill head including;

a housing separate from said base, said housing having;

a first opening;

a second opening;

and an attachment feature adjacent the second opening wherein, said housing is shaped to be mounted to said base;

a cutting device disposed in said housing, said cutting device being positioned in said housing between the first and second housing openings and having at least one cutting feature for cutting bone stock introduced into the housing first opening into bone chips and defining an opening through which the bone chips pass so that the bone chips are discharged through the housing second opening wherein, said cutting device is moveably disposed in said housing to move across the first and second housing openings; and

a cutting device coupling feature integral with said cutting device for releasably engaging said motor coupling feature so that when said coupling features are engaged, actuation of said motor results in the movement of said cutting device across the housing openings;

a catch tray, said catch tray having;

an open end;

a lip that extends upwardly from the open end;

and an attachment feature that cooperates with said housing attachment feature so that said attachment features removably hold said catch tray to said housing adjacent the housing second opening so that said catch tray and said mill head can be coupled to said base as a unitary assembly and so the bone chips discharged through the housing second opening are discharged into the open end of said catch tray and so that, upon removal of said catch tray from said housing, said catch tray lip passes across a portion of said cutting device that extends across the housing second opening; and

a locking assembly for releasably holding said mill head housing to said base in a position so that said coupling features can engage.

2. The bone mill of claim 1, wherein:

said mill head housing is formed so that the second opening is in registration with and below the first opening;

said cutting device is a cutting disc shaped to have at least one cutting edge that defines the cutting device opening, said cutting edge being part of the at least one cutting feature, said cutting disc being positioned between the first and second openings of said housing and being rotatably mounted in said housing so that a section of said cutting disc that defines the at least one cutting edge and the cutting device opening rotates below the housing first opening; and

said mill head includes an impingement plate separate from said housing that is statically mounted to said housing adjacent the first opening and positioned so that, as said cutting disc rotates, the at least one cutting edge rotates towards said impingement plate.

3. The bone mill of claim 1, wherein:

said cutting device is mounted in said mill head housing so that, in addition to being able to move across the housing openings, said cutting device engages in a supplemental movement within said housing; and

said motor and said cutting device are provided with complementary alignment features that engage when said mill head housing is mounted to said base wherein, the engagement of said alignment features causes supplemental movement of said cutting device that results in said cutting device coupling feature aligning with said motor coupling feature.

4. The bone mill of claim 1, wherein:

said mill head housing is further shaped so that the second opening is in registration with the first opening;

an impingement plate separate from said mill head housing is statically mounted to said housing adjacent the first opening so that said cutting device is located between said impingement plate and said housing second opening; and

a plunger is moveably mounted in said housing first opening to push bone stock against said cutting device.

5. The bone mill of claim 1, wherein:

said mill head housing has a first shell and a second shell that are secured together so that said mill head housing is a single piece unit; and

said cutting device is shaped and positioned between said shells so that said at least one cutting feature is disposed between said shells.

6. The bone mill of claim 1, wherein:

said mill head housing and said catch tray are collectively arranged so that said catch tray is located below said housing; and

said base has;

a foot;

a leg that extends away from said foot; and

a pedestal mounted to said leg, said pedestal being shaped to receive said mill head housing and having a notch in which said catch tray is seated, wherein said leg is dimensioned so that when said mill head housing is disposed on said pedestal, said catch tray is spaced above said foot.

7. The bone mill of claim 1, wherein said catch tray attachment feature is at least one flange that extends outwardly from said catch tray so as to extend outwardly from the open end of said catch tray.

8. The bone mill of claim 1, wherein said mill head housing attachment feature is at least one rail that extends from an outer surface of said housing.

9. The bone mill of claim 8, wherein said at least one rail is located so as to be spaced away from the second opening of said housing.

10. A bone mill, said bone mill including:

a base;

a motor disposed in said base;

a motor coupling feature connected to said motor; and

a mill head, said mill head including;

a housing separate from said base, said housing having first, second and third openings wherein, said housing is shaped to be mounted to said base;

a cutting device disposed in said housing, said cutting device being positioned in said housing between the first and second housing openings and having at least one cutting feature for cutting bone stock introduced into the housing first opening into bone chips and defining an opening through which the bone chips pass so that the bone chips are discharged through the housing second opening wherein, said cutting device is moveably disposed in said housing to move across the first and second housing openings; and

a cutting device coupling feature integral with said cutting device for releasably engaging said motor coupling feature so that when said coupling features are engaged, actuation of said motor results in the movement of said cutting device across the housing first and second openings wherein, said cutting device coupling feature is accessible through the mill head housing third opening for engagement by said motor coupling feature;

a catch tray;

interlocking attachment features integral with both said housing and said catch tray for removably holding said catch tray to said housing adjacent the housing second opening so that said catch tray and said mill head can be coupled to said base as a unitary assembly and so the bone chips discharged through the housing second opening are discharged into said catch tray; and

a locking assembly for releasably holding said mill head housing to said base in a position so that said coupling features can engage.

11. The bone mill of claim 10, wherein:

said mill head housing is formed so that the second opening is in registration with and below the first opening;

said cutting device is a cutting disc shaped to have at least one cutting edge that defines the cutting device opening, said cutting edge being part of the at least one cutting feature, said cutting disc being positioned between the first and second openings of said housing and being rotatably mounted in said housing so that a section of said cutting disc that defines the at least one cutting edge and the cutting device opening rotates between the housing first and second openings; and

said mill head includes an impingement plate separate from said housing that is statically mounted to said housing adjacent the first opening and positioned so that, as said cutting disc rotates, the at least one cutting edge rotates towards said impingement plate.

12. The bone mill of claim 10, wherein:

said catch tray has an open end into which the bone chips are discharged and a lip that extends upwardly from the open end; and

said catch tray is positioned relative to said mill head housing, said lip being located and said housing and said catch tray interlocking attachment features are configured so that, as the catch tray is removed from said mill head housing, the lip passes across a portion of said cutting device that extends across the housing second opening.

13. The bone mill of claim 10, wherein:

said cutting device is mounted in said mill head housing so that, in addition to being able to move across the housing first and second openings, said cutting device engages in a supplemental movement within said housing; and

said motor and said cutting device are provided with complementary alignment features that engage when said mill head housing is mounted to said base wherein, the engagement of said alignment features causes supplemental movement of said cutting device that results in said cutting device coupling feature aligning with said motor coupling feature.

14. The bone mill of claim 10, wherein said mill head housing has a void space in which said cutting device and said cutting device coupling feature are located and said mill head housing is further formed to have a ring that projects into the void space and that extends around the housing third opening so as to be between said cutting device at least one cutting feature and the housing third opening.

15. The bone mill of claim 10, wherein:

said mill head housing is a single piece unit that has first and second shells wherein, said first shell is formed with the housing first opening and said housing second shell is formed to define the housing second opening and the housing third opening; and

said cutting device is disposed between said housing shells.

16. The bone mill of claim 10, wherein:

said mill head housing is further shaped so that the second opening is in registration with the first opening;

an impingement plate separate from said mill head housing is statically mounted to said housing adjacent the housing first opening so that said cutting device is located between said impingement plate and said housing second opening; and

a plunger is moveably mounted in said housing first opening to push bone stock against said cutting device.

17. The bone mill of claim 10, wherein:

said base has a surface on which said bone mill housing is seated; and

said motor is mounted to said base and said motor coupling feature is connected to said motor so that said motor coupling feature projects above the base surface so that, when said bone mill housing is mounted to said base, said motor coupling feature extends into the housing third opening.

18. The bone mill of claim 10, wherein said mill head housing has a void space in which said cutting device and said cutting device coupling feature are located and said cutting device coupling feature does not extend through the housing third opening.

19. The bone mill of claim 10, wherein:

said base includes a pedestal on which said mill head housing is seated and said pedestal is formed define a notch;

said mill head housing and catch tray attachment features hold said catch tray to said mill head housing so that said catch tray is located below said mill head housing; and

said catch tray is shaped so that when said mill head is seated on said pedestal, said catch tray is disposed in the base pedestal notch.

20. The bone mill of claim 10, wherein said mill head cutting device is a single piece disc shaped to have a plurality of said cutting features.