Metal deforming – Process – Deforming sheet metal
Patent
1995-05-17
1998-11-10
Sipos, John
Metal deforming
Process
Deforming sheet metal
72348, 413 67, 413 15, B21D 5144
Patent
active
058327703
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for further treating a closure end made of sheet, particularly a folding end for beverage cans or the like. The tool for carrying out the process is also concerned.
2. Prior Art
Such an end is known from U.S. Pat. No. 3,441,170, where the radius of curvature itself is reduced in thickness from the inner side of the end thereby forming a bead ("coined bead"). In this way, kind of a joint is created between the inner leg of the groove and the central panel portion to restrict the bulging of the end to the central panel portion so as to reduce the tensile forces acting radially inwardly upon the core wall of the end. At this joint (coined bead), the central panel portion bulging more strongly under the increased internal pressure, is pivoted to the core wall such that the bulging does not affect or only affects slightly the latter as regards its vertical orientation.
EP 88 968 A1 discloses a similar measure in which, starting from the radially inner edge of the radius of curvature', the end sheet is externally deformed over an area of the radius of curvature' by pressing power, so that material of the end flows radially inwardly and outwardly from this radius of curvature region. The deformation region forms a flattening on the outer side of the radius of curvature', the major portion of the flattening being disposed in a plane perpendicular to the end axis or in a conical plane inclined outwardly and downwardly. This also serves for improving the resistance of the end to bulging. Owing to the flow of the material radially inwardly, compressive strain is applied to the outwardly bulged central panel portion thereby forming a free bulging ("free doming of central panel"), while the material flowing radially outwardly pivots permanently the inner leg of the groove U-shaped in cross-section from its original, inclined position into a position which is more cylindrical or parallel to the end axis ("permanent deflection of inner leg"). In the two known measures, the region deformed by coining ("coining") is simultaneously hardened by cold working ("work hardened"). Both prior art solutions strive to obtain an enlarged bulging of the central panel portion ("doming"). However, if a filled can provided with such a considerably bulged end is pasteurized, for example (it being placed upside down in this case), the resulting bulging will cause the cans to tip and fall over.
SUMMARY OF THE INVENTION
It is the object of this invention to modify an end by a process in such a way that the bulging of the end center can largely be reduced and nevertheless material from the end edge portion can be displaced in controlled fashion to increase the resistance to pressure.
In this connection, the annular fringe region which is formed in the further treatment accompanied by a reduction in thickness, is clearly positioned radially inside the actual radius of curvature'. This means that almost no material is displaced into the central panel portion but out of its edge portion, via the radius of curvature and (almost exclusively) into the radially inner leg of the U-shaped core groove. This displacement process is achieved, above all, by the angle which is formed and defined by the coining areas actuating upon the fringe-like region. This angle is defined between the coining areas of the coining tool or coining die actuating externally upon the end and a plane extending perpendicularly to the end axis. In this connection, the coining area of the lower coining tool or coining die is preferably parallel to this plane extending perpendicularly to the end axis, which means that said angle also exists between the two coining areas. This angle is to be markedly greater than 0.degree., but in any case less than 90.degree..
This angle is preferably between 2.degree. and 15.degree..
Ends reshaped in such a way are stable as regards their upside-down stability even at increased internal pressure even though they do not have to miss the advantage
REFERENCES:
patent: Re33217 (1990-05-01), Nguyen
patent: 2154983 (1939-04-01), Jeune
patent: 3441170 (1969-04-01), Khoury
patent: 3576272 (1971-04-01), Colby
patent: 3591037 (1971-07-01), Schrecker
patent: 3946683 (1976-03-01), Jordan
patent: 4122791 (1978-10-01), Brown
patent: 4354784 (1982-10-01), Westphal
patent: 4434641 (1984-03-01), Nguyen
patent: 4577774 (1986-03-01), Nguyen
patent: 4579495 (1986-04-01), Dassler
patent: 4735863 (1988-04-01), Bachmann
patent: 4832223 (1989-05-01), Kalenak
patent: 5219257 (1993-06-01), Koch
patent: 5356256 (1994-10-01), Turner
Heinecke Dieter
Hoft Peter
Strube Lutz
Day Christopher W.
Schmalbach-Lubeca AG
Sipos John
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