Expanding collet assembly

• US 5,397,135 A
• Filed: 07/01/1993
• Issued: 03/14/1995
• Est. Priority Date: 07/01/1993
• Status: Expired due to Term

• Current Assignee: Hardinge Incorporated (InCompass LLC)
• Original Assignee: Hardinge Brothers Incorporated
• Inventors: Smith, Roger R.
• Primary Examiner(s): Bishop, Steven C.
• Application Number:
  US08/084,151
• Time in Patent Office: 621 Days
• Field of Search: 279/2.01-2.04, 279/51, 279/58, 279/2.09, 279/156, 279/157, 269/48.1, 82/169, 242/68.2, 242/72 R, 409/233
• US Class Current: 279/2.04
• CPC Class Codes: B23B 31/4033 using mechanical transmission through the spindle B23B31/4026 takes precedence
• CPC Class Codes: Y10T 279/1012 Fixed cam and moving jaws
• CPC Class Codes: Y10T 279/3487 Tool or work stop or locator
• CPC Class Codes: Y10T 279/3493 Protection means; e.g., cover, seal, overstress prevention, air blast

Abstract

An expanding collet assembly comprises an arbor having a flange portion for securing to a machine tool spindle and a shaft portion extending from the flange portion. The shaft portion includes a first conical surface disposed at its free end and a second conical surface disposed adjacent the flange portion. Conical surfaces are parallel to each other and disposed radially inwardly in the direction away from the flange portion. An expanding collet having alternately disposed slots to form a plurality of fingers extend inwardly from opposite collet ends and have inner conical surfaces at the collet ends that cooperate with the first and second conical surfaces. The expanding collet is axially slidably disposed around the shaft portion between a relaxed position when the collet is disposed away from the flange portion and an expanded position when disposed toward the flange portion. A draw plug with a flanged head in engagement with one end of the collet is disposed axially through the arbor in an opening in the shaft portion. A draw bar adapter is disposed within a recess in the arbor and secures one end of the draw plug, the adapter being secured to a draw bar for axially actuating the draw plug, thereby actuating the collet. An annular work locating stop is secured to the flange portion and overlies at least a portion of the collet, the stop having an annular free edge for abutting against a workpiece. Another embodiment of the expanding collet assembly for smaller workpieces is also disclosed.

Claims

1. A collet assembly, comprising:

an arbor including a flange portion having a tapered annular recess constructed and arranged to cooperate with an annular tapered projection of a machine tool spindle for centering said arbor with respect to said machine tool spindle when said arbor is coupled thereto, said arbor including a shaft portion extending from said flange portion;

said shaft portion including a first conical surface disposed at its free end and a second conical surface disposed adjacent said flange portion;

said first and second conical surfaces being parallel to each other and disposed radially inwardly in the direction away from said flange portion;

an expanding collet having alternately disposed slots to form a plurality of fingers extending inwardly from opposite collet ends and having inner conical surfaces at said collet ends that cooperate with said first and second conical surfaces;

said expanding collet being axially slidably disposed around said shaft portion between a relaxed position when said collet is disposed away from said flange portion and an expanded position when disposed toward said flange portion;

a draw plug disposed axially through said arbor in an opening in said shaft portion, said plug having a flanged head in engagement with one end of said collet;

a draw bar adapter disposed within a recess in said arbor and securing one end of said draw plug, said adapter being secured to a draw bar for axially actuating said draw plug, thereby actuating said collet;

an annular work locating stop secured to said flange portion and overlying at least a portion of an annular periphery of said collet, said stop having an annular free edge for abutting against a workpiece; and

a key screw disposed on said arbor and engaging said adapter to prevent relative motion of said adapter with said arbor.

2. A collet assembly as in claim 1, further comprising:

a pin disposed in said shaft portion, said pin having a portion protruding above the surface of said shaft portion; and

said collet includes a recess adapted to slidably receive said pin, said recess has a base that engages said pin when said collet is in said expanded position.

3. A collet assembly as in claim 1, further comprising a seal disposed in said shaft opening between said shaft portion and said plug.

4. A collet assembly as in claim 3, wherein said seal is carried by said plug.

5. A collet assembly as in claim 1, wherein:

said expanding collet slots each includes a base connecting adjacent said fingers; and

said base is disposed below the outer cylindrical surface of said collet.

6. A collet assembly as in claim 5, wherein said base includes said collet conical surfaces.

7. A collet assembly as in claim 1, wherein said work locating stop is removably secured to said arbor.

8. A collet assembly as in claim 1, wherein said work locating stop is machinable.

9. A collet assembly as in claim 1, wherein said adapter is machinable to adapt to the draw bar.

10. A collet assembly, comprising:

an arbor, including a shaft portion at a first end and a threaded bushing at a second end for securing to a machine tool spindle and draw bar, said second end including a tapered annular recess constructed and arranged to cooperate with an annular tapered projection of the machine tool spindle for centering said arbor with respect to the machine tool spindle when said arbor is coupled thereto;

a work locating stop adaptor mounted on the arbor adjacent to said shaft portion;

said shaft portion including a first conical surface disposed at its free end and a second conical surface disposed adjacent said work locating stop adaptor;

said first and second conical surfaces being parallel to each other and disposed radially inwardly in the direction away from said work locating stop adaptor;

an expanding collet having alternately disposed slots to form a plurality of fingers extending inwardly from opposite collet ends and having inner conical surfaces at said collet ends that cooperate with said first and second conical surfaces;

said expanding collet being axially slidably disposed around said shaft portion between a relaxed position when said collet is disposed away from said work locating stop adaptor and an expanded position when disposed toward said work locating stop adaptor;

a draw plug disposed axially through said arbor in an opening in said shaft portion and being secured to a threaded end section of said opening, the threaded end section of said opening being connected to said threaded bushing of said arbor, said plug including a flanged head in engagement with one end of said collet; and

an annular work locating stop secured to said work locating stop adaptor and overlying at least a portion of an annular periphery of said collet, said stop having an annular free edge for abutting free edge for abutting against a workpiece.

11. A collet assembly as in claim 10, further comprising:

a pin disposed in said shaft portion, said pin having a portion protruding above the surface of said shaft portion; and

said collet includes a recess adapted to slidably receive said pin, said recess has a base that engages said pin when said collet is in said expanded position.

12. A collet assembly as in claim 10, further comprising a seal disposed in said shaft opening between said shaft portion and said plug.

13. A collet assembly as in claim 12, wherein said seal is carried by said plug.

14. A collet assembly as in claim 10, wherein:

said expanding collet slots each include a base connecting adjacent said fingers; and

said base is disposed below the outer cylindrical surface of said collet.

15. A collet assembly as in claim 14, wherein said base includes said collet conical surfaces.

16. A collet assembly as in claim 10, wherein said work locating stop is machinable.

17. A collet assembly, comprising:

an arbor including a flange portion having a tapered annular recess constructed and arranged to cooperate with an annular tapered projection of a machine tool spindle for centering said arbor with respect to the machine tool spindle when said arbor is coupled thereto, said arbor including a shaft portion extending from said flange portion;

said shaft portion including a first conical surface disposed at its free end;

said conical surface being disposed radially inwardly in the direction away from said flange portion;

an expanding sleeve having a plurality of slots to form a plurality of fingers extending outwardly away from said flange portion toward its free end from intermediate said sleeve and having inner conical surfaces at said free end that cooperate with said sleeve conical surfaces;

said expanding sleeve being axially slidably disposed around said shaft portion between a relaxed position when said sleeve is disposed away from said flange portion and an expanded position when disposed toward said flange portion;

a draw plug disposed axially through said arbor in an opening in said shaft portion, said plug having a flanged head in engagement with one end of said sleeve;

a draw bar adapter coupled to an end of said draw plug, said adapter being secured to a draw bar for axially actuating said draw plug, thereby actuating said collet;

an expanding collet having a portion overlying said expanding sleeve and a nose portion extending axially from said overlying portion, said expanding collet having a plurality of slots disposed toward its free end away from said flange portion, said expanding collet being adapted to expand when said expanding sleeve is expanded;

said nose portion being adapted to be inserted internally into a workpiece;

an annular stop disposed around said expanding collet overlying portion, said stop having an annular free edge for abutting against a workpiece; and

a set screw disposed in said arbor engaging said adapter to prevent relative motion of said adapter with said arbor.

18. A collet assembly as in claim 17, further comprising:

a pin disposed in said shaft portion, said pin having a portion protruding above the surface of said shaft portion; and

said expanding sleeve includes a recess adapted to slidably receive said pin, said recess has a base that engages said pin when said sleeve is in said expanded position.

19. A collet assembly as in claim 17, further comprising a seal disposed in said shaft opening between said plug and said shaft portion.

20. A collet assembly as in claim 19, wherein said seal is carried by said plug.

21. A collet assembly as in claim 17, wherein said expanding collet is removably secured to said flange portion.

22. A collet assembly as in claim 17, wherein said stop is machinable.

23. A collet assembly as in claim 17, wherein said adapter is machinable.

24. A collet assembly, comprising:

an arbor including a flange portion for securing to a machine tool spindle and a shaft portion extending from said flange portion, said shaft portion including a first conical surface disposed at its free end, said conical surface being disposed radially inwardly in the direction away from said flange portion;

an expanding sleeve having a plurality of slots to form a plurality of fingers extending outwardly away from said flange portion toward its free end from intermediate said sleeve and having inner conical surfaces at said free end that cooperate with said sleeve conical surfaces, said expanding sleeve being axially slidably disposed around said shaft portion between a relaxed position when said sleeve is disposed away from said flange portion and an expanded position when disposed toward said flange portion;

a draw plug disposed axially through said arbor in an opening in said shaft portion, said plug having a flanged head in engagement with one end of said sleeve;

a draw bar adapter disposed within a end of said draw plug, said adapter being secured to a draw bar for axially actuating said draw plug, thereby actuating said collet;

an expanding collet having a portion overlying said expanding sleeve and a nose portion extending axially from said overlying portion, said expanding collet having a plurality of slots disposed toward its free end away from said flange portion, said expanding collet being adapted to expand when said expanding sleeve is expanded;

said nose portion being adapted to be inserted internally into a workpiece; and

an annular stop disposed around said expanding collet overlying portion, said stop having an annular free edge for abutting against a workpiece,

said nose portion being substantially solid, said collet overlying portion slots having a first width and said nose portion slots disposed at the periphery having a second width and within the interior a third width.

25. A collet assembly, comprising:

an arbor including a flange portion having a..tapered annular recess constructed and arranged to cooperate with an annular tapered projection of a machine tool spindle for centering said arbor with respect to said machine tool spindle when said arbor is coupled thereto, said arbor including a shaft portion extending from said flange portion;

said shaft portion including a first conical surface disposed at its free end and a second conical surface disposed adjacent said flange portion;

said first and second conical surfaces being parallel to each other and disposed radially inwardly in the direction away from said flange portion;

an expanding collet having alternately disposed slots to form a plurality of fingers extending inwardly from opposite collet ends and having inner conical surfaces at said collet ends that cooperate with said first and second conical surfaces;

said expanding collet being axially slidably disposed around said shaft portion between a relaxed position when said collet is disposed away from said flange portion and an expanded position when disposed toward said flange portion;

a draw plug disposed axially through said arbor in an opening in said shaft portion, said plug having a flanged head in engagement with one end of said collet;

a draw bar adapter disposed within a recess in said arbor and securing one end of said draw plug said adapter being secured to a draw bar for axially actuating said draw plug, thereby actuating said collet;

an annular work locating stop secured to said flange portion and overlying at least a portion of an annular periphery of said collet, said stop having an annular free edge for abutting against a workpiece; and

a set screw for locking said adapter with respect to said arbor,

said draw plug and said adapter including interengaging threads for securing said draw plug to said adapter, and said adapter including a threaded bore for threaded engagement with the draw bar,

said draw plug including a boss for engaging a surface of said adapter upon threaded interengagement of said draw plug and said adapter so that said draw plug is locked with respect to said arbor.

26. A collet assembly, comprising:

an arbor including a flange portion having a tapered annular recess constructed and arranged to cooperate with an annular tapered projection of a machine tool spindle for centering said arbor with respect to the machine tool spindle when said arbor is coupled thereto, said arbor including a shaft portion extending from said flange portion;

said shaft portion including a first conical surface disposed at its free end;

said conical surface being disposed radially inwardly in the direction away from said flange portion;

an expanding sleeve having a plurality of slots to form a plurality of fingers extending outwardly away from said flange portion toward its free end from intermediate said sleeve and having inner conical surfaces at said free end that cooperate with said sleeve conical surfaces;

said expanding sleeve being axially slidably disposed around said shaft portion between a relaxed position when said sleeve is disposed away from said flange portion and an expanded position when disposed toward said flange portion;

a draw plug disposed axially through said arbor in an opening in said shaft portion, said plug having a flanged head in engagement with one end of said sleeve;

a draw bar adapter coupled to an end of said draw plug, said adapter being secured to a draw bar for axially actuating said draw plug, thereby actuating said collet;

an expanding collet having a portion overlying said expanding sleeve and a nose portion extending axially from said overlying portion, said expanding collet having a plurality of slots disposed toward its free end away from said flange portion, said expanding collet being adapted to expand when said expanding sleeve is expanded;

said nose portion being adapted to be inserted internally into a workpiece;

an annular stop disposed around said expanding collet overlying portion, said stop having an annular free edge for abutting against a workpiece; and

a set screw for locking said adapter with respect to said arbor,

said draw plug and said adapter including interengaging threads for securing said draw plug to said adapter, and said adapter including a threaded bore for threaded engagement with the draw bar,

said draw plug including a boss for engaging a surface of said adapter upon threaded interengagement of said draw plug and said adapter so that said draw plug is locked with respect to said arbor.