Metal Containers and Methods of Manufacture
AssigneeCrown Packaging Technology, Inc.
InventorPaul Robert Dunwoody
Life of this patent
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Abstract
A method of reducing a thickness and increasing a height of a cylindrical wall of a metal cup to form a can body comprises positioning a wall-ironing punch inside the cup, moving an annular wall-ironing die axially over the closed end of the cup towards the open end of the cup, but not beyond the open end of the cup, in order to iron the cylindrical wall from the closed end up to a position axially spaced from the open end and moving the wall-ironing die back in an opposite direction to remove the can body from the die. Methods of altering a diameter of one or more regions of a can body are also disclosed.
Claims19
A method of reducing a thickness and increasing a height of a cylindrical wall of a metal cup so as to form a can body, the method comprising:
- positioning a wall-ironing punch inside the cup;
- moving an annular wall-ironing die axially over the closed end of the cup towards the open end of the cup, but not beyond the open end of the cup, in order to iron the cylindrical wall from the closed end up to a position axially spaced from the open end;
- and
- moving the wall-ironing die back in an opposite direction to remove the can body from the die.
A method of increasing a diameter of at least one region of a can body having an open end surrounded by a flange, the method comprised by:
- clamping the flange;
- and
- pushing a punch having a number of portions of different diameters, into the can body, through the open end, wherein a first portion of the punch has a diameter that provides a small clearance between the punch and an inner surface of the can body, such that a region of the can body adjacent a closed end of the end body is substantially not increased.
A method of reducing a diameter of one or more regions of a can body by:
- pushing an annular tool having a number of portions of different diameter axially over the can body;
- and
- pushing a punch inside the can body, the punch having a number of portions of different diameter, wherein at least one portion has a diameter corresponding to a desired reduced can body diameter, to form the can body wall against the punch.
A method of increasing a diameter of one or more regions of a can body by:
- pushing an annular tool having a number of portions of different diameter axially over the can body;
- and
- pushing a punch inside the can body, the punch having a number of portions of different diameter, wherein at least one portion has a diameter corresponding to a desired increased can body diameter, to form the can body wall against the punch.
Dependencies are inferred from the claim text.