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US 4,571,978 AGranted
Method of and apparatus for forming a reinforced can end
AssigneeMetal Box Limited
InventorsWilliam L. Taube, David A. Roberts
Life of this patent
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AssigneeMetal Box Limited
InventorsWilliam L. Taube, David A. Roberts
Estimating the term…
The invention herein relates to a method of and apparatus forming a reinforced pressure resistant can end by gripping a central panel of a metallic blank between an axially aligned reform pad and an indent ring, the reform pad being in internal concentric relationship to a draw punch and the indent ring being in internal concentric relationship to a lift ring, the draw punch being movable in a first direction to exert first forces against a peripheral edge portion of the blank in a first direction to form the peripheral edge portion out of the plane of the central panel and shape the blank into a generally flanged cup-shaped configuration defined by the central panel, a radius, a frusto-conical wall and an annular flange, and while the central panel is still gripped, second forces are exerted beyond the first forces and in a second direction opposite the first direction to form at least a part of the metal of the radius, in the absence of restraint or constraint, out of the plane of the central panel and to a side thereof opposite the flange to form an annular reinforcing countersink radius.
A method of forming a reinforced pressure-resistant can end comprising the steps of providing a generally planar metallic blank having a central portion and an outboard peripheral edge portion, exerting first forces against the peripheral edge portion of the blank in a first direction to deform the peripheral edge portion out of the plane of the central portion and shape the blank into a generally flanged cup-shaped configuration defined by the central portion, a radius, a frusto-conical wall and a shallow annular channel-like flange opening in a direction toward the central portion, and exerting second forces greater than the first forces against the flange in a second direction opposite the first direction while gripping the central portion to deform at least a part of the metal of the radius in the absence of restraint out of the plane of the central portion plane, to a side thereof opposite the flange, and in the same direction as the opening direction of the flange;
Apparatus for forming a reinforced pressureresistant can end comprising means for creating a generally circular planar metallic blank having a central portion and an outboard peripheral edge portion, first force exerting means for exerting first forces against the peripheral edge portion of the blank in a first direction to deform the peripheral edge portion out of the plane of the central portion and shape the blank into a generally flanged cup-shaped configuration defined by the central portion, a radius, a frusto-conical wall and a shallow annular channel-like flange opening in a direction toward the central portion, gripping means for gripping the central portion, and second force exerting means for exerting second forces greater than the first forces against the flange in a second direction opposite the first direction while said gripping means are gripping the central portion to deform at least a part of the metal of the radius in the absence of restraint out of the plane of the central portion plane, to a side thereof opposite the annular flange to thereby form an annular reinforcing countersink radius, and in the same direction as the opening direction of the flange;
Apparatus for forming a reinforced pressure-resistant can end comprising means for creating a generally circular planar metallic blank having a central portion and an outboard peripheral edge portion, means for forming the peripheral edge portion into a generally cylindrical wall thereby defining with the central portion a generally shallow cup-shape shell, first force exerting means for exerting first forces against the cup-shaped shell in a first direction to reshape the shallow cup-shape shell into a generally flanged cup-shaped shell defined by the central portion, a radius, a frusto-conical wall and a shallow annular channel-like flange with the flanged cup-shaped shell opening in a direction opposite to that of the shallow cup-shaped shell and toward the central portion, and second force exerting means for exerting second forces greater than the first forces against a central portion of the flanged cup-shaped shell in a second direction opposite the first direction to deform at least a part of the metal of the radius in the absence of restraint out of the plane of the central portion plane, to a side thereof opposite the annular flange to thereby form an annular reinforcing countersink radius, and in the same direction as the opening direction of the flange;
Dependencies are inferred from the claim text.