Claims
- 1. A progressive die for forming a collared hole in a sheet of material comprising:
- a main frame;
- a plurality of spaced apart first punches mounted on said main frame at a first station and arranged in a pattern about a center point;
- a plurality of first bushings mounted on said main frame at said first station and arranged in said pattern to receive said first punches and form a plurality of first holes in a sheet of material leaving material extending between said holes;
- a main punch mounted on said main frame at a second station;
- a main bushing mounted on said main frame to receive said main punch removing some of said material extending between said holes forming a main hole in said sheet of material and leaving portions of material extending inwardly in said main hole;
- a straightening punch mounted on said main frame at a third station;
- a straightening busing mounted on said main frame to receive said straightening punch to bend said portions outwardly and form a collared hole in said sheet of material, said straightening punch having an outside diameter larger than said main punch to first draw material continuously around said main hole and then bend said portions outwardly forming a collar continuously surrounding said main hole; and,
- means for forcing a sheet of material through the die and stopping said sheet of material sequentially at said first station, said second station and said third station.
- 2. The die of claim 1 wherein:
- said first punches each have an outer forming surface located an equal distance from said center point, said main punch is sized relative to said equal distance to insure said main hole formed by said main punch breaks into said first holes.
- 3. The die of claim 1 and further comprising:
- a curling punch mounted on said main frame at a fourth station; and,
- a curling bushing mounted on said main frame at said fourth station to receive said curling punch forming a continuous curl atop said collar.
- 4. A progressive die for producing collared holes in a sheet of material comprising:
- a main frame;
- at least three spaced apart first punches of the same diameter mounted on said main frame at a first station and arranged in a pattern an equal distance from and around a center point;
- at least three spaced apart bushings mounted on said main frame at said first station and arranged in said pattern to receive said punches and form at least three spaced apart holes in said pattern in a sheet of material leaving material extending between said holes;
- a first main punch having a longitudinal axis and mounted on said main frame at a second station, said main punch having a circular cross section of a first radius greater than said equal distance;
- a main bushing mounted on said main frame and centered relative to said axis to receive said main punch removing some of said material extending between said holes when said three spaced apart holes formed in a pattern about a center point are centered relative to said axis forming a single hole from said three holes in said sheet of material and leaving portions of material extending inwardly in said main hole;
- a straightening punch mounted on said main frame at a third station;
- a straightening bushing mounted on said main frame to receive said straightening punch to bend said portions outwardly and form a collared hole in said sheet of material; and,
- means for forcing said sheet of material through the die and stopping said sheet of material sequentially at said first station, said second station and said third station.
- 5. The die of claim 4 and further comprising:
- a press plate having said three punches, said main punch and said straightening punch mounted thereon; and,
- an additional plate having said three bushings, said main bushing and said straightening bushing mounted thereon.
- 6. The die of claim 4 and further comprising:
- an indexing rod mounted to said main frame after said first station to extend into one of said three holes precisely locating said sheet as said sheet is moved to other stations.
- 7. The die of claim 4 and further comprising:
- a second main punch mounted on said main frame at said second station, said second main punch having a circular cross section of a radius greater than said equal distance but less than said first radius to remove less material and produce a longer collar height than said first main punch;
- a second main bushing mounted on said main frame to receive said second main punch removing some of said material extending between said holes forming a single hole from said three holes in said sheet of material and leaving portions of material extending inwardly in said second main hole; and,
- limit means associated with said first main punch and said second main punch and operable to limit movement of said first main punch and said second main punch toward said sheet depending upon the desired collar height.
- 8. The die of claim 7 and further comprising:
- a curling punch mounted on said main frame at a fourth station; and,
- a curling bushing mounted on said main frame at said fourth station to receive said curling punch forming a continuous curl atop said collar.
Parent Case Info
This application is a division, of application Ser. No. 462,618, filed Jan. 9, 1990.
US Referenced Citations (4)
Non-Patent Literature Citations (1)
Entry |
King, J. A., "Progressive Die Produces Safety Runway", from American Machinist, Nov. 6, 1947, pp. 128-131. |
Divisions (1)
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Number |
Date |
Country |
Parent |
462618 |
Jan 1990 |
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