Can end and method for fixing the same to a can body
AssigneeCrown Cork & Seal Technologies Corporation
InventorsMouayed Mamdooh Brifcani, Peter James Hinton, Mark Christopher Kysh
Life of this patent
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Abstract
A can end (22) comprising a peripheral cover hook (23), a chuck wall (24) dependent from the interior of the cover hook, an outwardly concave annular reinforcing bead (25) extending radially inwards from the chuck wall, and a central panel (26) supported by an inner portion (27) of the reinforcing bead, characterised in that, the chuck wall (24) is inclined to an axis perpendicular to the exterior of the central panel at an angle between 20° and 60°, and the concave cross-sectional radius of the reinforcing bead (25) is less than 0.75 mm.
Claims10
A can end comprising a peripheral cover hook, (23) a chuck wall (24) dependent from the interior of the cover hook, an outwardly concave annular reinforcing bead (25) extending radially inwards from the chuck wall, and a central panel (26) supported by an inner portion (27) of the reinforcing bead, characterised in that, the chuck wall (24) is inclined to an axis perpendicular to the exterior of the central panel (26) at an angle C between 30° and 60°, and the concave cross sectional radius of the reinforcing bead (25) is less than 0.75 mm.
A can end according to any preceding claim characterised in that the ratio of the diameter of the central panel to the diameter of the peripheral curl is 80% or less.
A can end according to any preceding claim characterised in that it is made of a laminate of thermoplastic polymer film and a sheet aluminium alloy or tinplate or electrochrome coated steel.
A method of forming a double seam between a can body (12) and a can end (22) according to any preceding claim, said method comprising the steps of:
- placing the curl (23) of the can end on a flange (11) of a can body supported on a base plate (4);
- locating a chuck (30) within the chuck wall (24) of the can end, said chuck having a frustoconical drive surface (32) of substantially equal slope B° to that of the chuck wall of the can end and a substantially cylindrical surface portion (33) extending away from the drive surface;
- causing relative motion as between the assembly of can end and can body and a first operation seaming roll (34) to form a first operation seam, and thereafter causing relative motion as between the first operation seam and a second operation roll (38) to complete a double seam, during these seaming operations the chuck wall (24) of the can becoming bent to contact the cylindrical portion (33) of the chuck.
Dependencies are inferred from the claim text.