Claims
- 1. A method, comprising the steps of:
- (a) cutting a metal blank from a rolled sheet of metal having a stock thickness and a rolling direction; and
- (b) forming said metal blank into a container end comprising a center panel having a centerpoint and an outer periphery, an outer annular panel having an inner periphery, and an inner annular panel having an inner periphery and an outer periphery, and a generally uniform thickness substantially equal to the stock thickness of the sheet metal, the inner periphery of said inner annular panel being joined to the outer periphery of said central panel, the outer periphery of said inner annular panel being joined to the inner periphery of said outer annular panel; said inner annular panel having a generally arcuate cross section, viewed along a radial plane from the centerpoint of said central panel; said inner annular panel comprising:
- (i) a plurality of first segments about the circumferential length of said inner annular panel, and
- (ii) a plurality of second segments, with at least one first segment being positioned between each adjacent pair of second segments, the generally arcuate cross section of each of said first segments having a radius of curvature, viewed in radial cross section, which is substantially less than the radius of curvature, viewed in radial cross section, of the generally arcuate cross section of each of said second segments, the radius of curvature on the upward-facing surface of any said segment being substantially equal to the radius of curvature for the through-adjacent downward-facing surface to equally space said upward-facing surface and said downward-facing surface from one another throughout said segment.
- 2. The method of claim 1, wherein each second segment is positioned about said inner annular panel so that the center of the respective first segment, when viewed from the centerpoint of the central panel, is located in said inner annular panel at an angle which is in the range of about 70.degree. to about 110.degree. in either direction from a line parallel to the rolling direction of the rolled sheet material used to form the container end, said line extending through the centerpoint of the central panel.
- 3. The method of claim 2 wherein the difference between the radius of curvature of each of said plurality of first segments and the radius of curvature of each of said plurality of second segments is at least about 0.003 inch.
- 4. The method of claim 2 wherein the radius of curvature of each of said plurality of first segments is in the range of about 0.012 inch to about 0.025 inch, the radius of curvature of each of said plurality of second segments is in the range of about 0.017 inch to about 0.03 inch, and the difference between the radius of curvature of each of said plurality of first segments and the radius of curvature of each of said plurality of second segments is at least about 0.003 inch.
- 5. The method of claim 2 wherein the radius of curvature of each of said plurality of first segments about 0.015 inch and the radius of curvature of each of said plurality of second segments is about 0.025 inch.
- 6. The method of claim 2 further comprising the steps of:
- (c) providing a container body; and
- (d) forming a pressure resistant container by seaming said container end to said container body.
- 7. The method of claim 6 wherein the radius of curvature of each of said plurality of first segments is in the range of about 0.012 inch to about 0.025 inch, the radius of curvature of each of said plurality of second segments is in the range of about 0.017 inch to about 0.03 inch, and the difference between the radius of curvature of each of said plurality of first segments and the radius of curvature of each of said plurality of second segments is at least about 0.003 inch.
- 8. A die for forming different radii of curvature of a generally arcuate cross section along the circumferential length of an inner annular panel of a container end, the die comprising:
- (a) an outer annular edge having a generally arcuate cross section, said outer annular edge comprising,
- (i) a plurality of first segments spaced apart about the circumferential length of said outer annular edge, and
- (ii) a plurality of second segments, with at least one first segment being positioned between each adjacent pair of second segments,
- the generally arcuate cross section of each of said first segments having a radius of curvature, viewed in radial cross section, which is substantially less than the radius of curvature, viewed in radial cross section, of the generally arcuate cross section of each of said second segments.
- 9. The die of claim 8 wherein the radius of curvature, viewed in radial cross section, of each of said plurality of first segments is in the range of about 0.01 inch to about 0.025 inch, while the radius of curvature, viewed in radial cross section, of each of said plurality of second segments is in the range of about 0.015 inch to about 0.035 inch.
- 10. The die of claim 8 wherein the radius of curvature, viewed in radial cross section, of each of said plurality of first segments is in the range of about 0.012 inch to about 0.025 inch, the radius of curvature of each of said plurality of second segments, viewed in cross section, is in the range of about 0.017 inch to about 0.03 inch, and the difference between the radius of curvature of each of said plurality of first segments and the radius of curvature of each of said plurality of second segments is at least about 0.003 inch.
- 11. The die of claim 8 wherein the radius of curvature, viewed in cross section section, of each of said plurality of first segments is about 0.015 inch and the radius of curvature, viewed in cross section, of each of said plurality of second segments is about 0.025 inch.
- 12. A die for forming, from a rolled sheet of metal having a rolling direction, a container end having different radii of curvature of a generally arcuate cross section along the circumferential length of an inner annular panel at locations oriented with respect to said rolling direction, the die comprising:
- (a) a die body having an outer annular edge and being orientatable with respect to the rolling direction of a rolled sheet of metal;
- (b) said outer annular edge having a generally arcuate cross section and including:
- (i) a plurality of first segments spaced apart about the circumferential length of said outer annular edge, and
- (ii) a plurality of second segments, with at least one said first segment being positioned between each adjacent pair of said second segments, the generally arcuate cross section of each of said first segments having a radius of curvature, viewed in radial cross section, which is substantially less than the radius of curvature, viewed in radial cross section, of the generally arcuate cross section of each of said second segments; and
- (c) said first and second segments being positioned on said outer annular edge of said die body in relation to the orientation of said die body with respect to the rolling direction of said rolled sheet of metal.
- 13. A die for forming a container end according to claim 12, wherein the difference between the radius of curvature, viewed in cross section, of each of said plurality of first segments and the radius of curvature, viewed in cross section, of each of said plurality of second segments, is within the range of about 0.003 to 0.015 inch.
- 14. A die for forming a container end according to claim 12, wherein the center of each respective second segment is oriented on said outer annular edge of said die body at an angular orientation within the range of about 70 to 110 degrees in either direction with respect to said rolling direction of said sheet of metal.
- 15. A die for forming a container end according to claim 12, wherein a transition section is positioned between each said first and second segment;
- said transition section having a radius of curvature, viewed in cross section, having a range of values;
- said range of values for said radius of curvature of said transition section changing smoothly from a maximum value equal to the radius of curvature of said adjacent second segment to a minimum value equal to said radius of curvature of said adjacent first segment.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of U.S. patent application Ser. No. 08/342,737 filed Nov. 21, 1994 now U.S. Pat. No. 5,645,189.
US Referenced Citations (19)
Non-Patent Literature Citations (1)
Entry |
Hosford et al., "the Aluminum Beverage Can," Scientific American, Sep. 1994, pp. 48-53. |
Divisions (1)
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Number |
Date |
Country |
Parent |
342737 |
Nov 1994 |
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