Can end production

Abstract

A method of making a can end by forming a can end shell in a shell press; and converting the shell into a can end. The step of forming the can end shell includes pressing sheet metal into an end shell with a bead feature in the radially outer circumference of its centre panel. In a subsequent can end conversion operation material from the bead feature is used to set final geometry of the converted can end.

Claims

1. A method of making an easy open can end, the method comprising: forming a can end shell in a shell press, in which the step of forming the can end shell comprises: pressing a sheet metal material into the can end shell, the step of pressing the sheet metal material into the can end shell includes forming a seaming panel (2), a countersink bead (3) positioned below a center panel (4) in a press direction, and one or more features positioned above the center panel (4) in the press direction, transferring the can end shell to a conversion press, and, in a sequence of operations, moving the sheet metal material composing the one or more features inwardly towards a center of the can end shell to set a final geometry of the easy open can end.

2. The method according to claim 1, in which the step of pressing the sheet metal material forms a panel step by using a deep center pad in the shell press.

3. The method according to claim 1, in which the step of pressing the sheet metal material further comprises forming a dished center panel.

4. The method according to claim 1, in which the step of pressing the sheet metal material further comprises forming one or more steps in the center panel.

5. The method according to claim 1, in which the step of wherein the one or more features includes beads or corrugations in the center panel.

6. The method according to claim 1, in which the step of pressing the sheet metal material further comprises forming the countersink bead in a radially outer circumference of the center panel (4).

7. An apparatus for forming an easy open can end from an end shell, the apparatus comprising: a shell press with shell tooling having upper tooling including a punch having a punch nose and lower tooling comprising a die center pad and a die center ring, the punch nose being configured to form a countersink, the die center pad including a protrusion for forming a feature between the countersink and a center panel of the end shell, the feature being positioned above the center panel in a press direction and the countersink being positioned below the center panel in the press direction; and a conversion press with tooling stations for a sequence of operations, at least one of the tooling stations being adapted to move material from the feature of the end shell, formed in the shell press, inwardly towards a center of the center panel.

8. A method of making an easy open can end, the method comprising: pressing a sheet metal material in a shell press to set an initial geometry of the can end, the initial geometry of the can end including a seaming panel, a center panel, a countersink bead positioned below the center panel in a press direction, and one or more features positioned above the center panel in the press direction; transferring the can end shell to a conversion press; and moving the sheet metal material composing the one or more features inwardly towards a center of the can end to set a final geometry of the can end.

9. The method of claim 8, wherein in the final geometry of the can end, moving the sheet metal material inwardly forms one or more new features positioned below the center panel in the press direction.

10. The method of claim 9, wherein in the final geometry of the can end the one or more new features comprise a concave annular bead.

11. The method of claim 8, wherein in the initial geometry of the can end the one or more features comprise a convex annular bead.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) A preferred embodiment of the present invention is now described with reference to the drawings, in which

(2) FIG. 1 is a side section of a conventional end shell;

(3) FIG. 2 is a side section of an end shell in accordance with one example of the invention;

(4) FIG. 3 is a side section of a final converted end, formed from the shell of FIG. 2; and

(5) FIG. 4 is overlaid side sections of FIGS. 2 and 3.

(6) FIG. 5 is a side section of an end shell within a shell press.

(7) FIG. 6 is a side section of an end shell within a conversion press.

DESCRIPTION OF EMBODIMENTS

(8) FIG. 1 is a side section of a conventional end shell for forming a can end.

(9) FIG. 2 is a side section of a beaded shell according to one embodiment of the invention. The shell edge is formed with a peripheral curl 1. An annular seaming panel 2 is connected by a wall to countersink bead 3 which surrounds center panel 4. An upwardly convex annular bead 5 between the countersink 3 and the center panel 4 has been provided so as to provide material for use during conversion to an easy open end.

(10) By adding a feature such as bead 5 to the shell in a shell press 20, it is possible to move material inwardly of the countersink bead 3 to the center of the end. The material of the bead is moved in one of a sequence of operations in a conversion press 22 to reform the shell bead 5 into a step 6, a platform and annular bead 7 (FIG. 3).

(11) FIG. 4 is an overlay of the side sections of FIGS. 2 and 3. This demonstrates how extra material from the shell bead 5 is used in a panel step 6 and panel bead 7 in the converted end.

(12) Evaluation of performance of the converted end samples has observed that forming a converted end from the shell with a bead generally allows use of material which provides a stronger and more uniform converted shell with improved peak and burst performance.

(13) The invention has been described above by way of example only and changes may be made without departing from the scope of the invention as defined by the claims.