Drawing and ironing container stock and manufacturing methods
AssigneeNational Steel Corporation
InventorWilliam T. Saunders
Life of this patent
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Abstract
Continuous-strip process for improving ironing operations in the manufacture of drawn and ironed container bodies having a bottom wall and unitary sidewall. Strip surfaces are treated, in final cold reduction operations for flat rolled container stock, to produce sculptured surfaces with fine line impressions to hold lubricant on the exterior surface of the sidewall during ironing and to reduce intimate surface contact with the ironing mandrel on the interior surface. Electroplated protective coatings are not reflowed in order to maintain the surface indentations.
Claims7
In the production of flat rolled sheet metal for use in manufacture of a drawn and ironed cup-shaped container body having a bottom wall and a unitary sidewall,
- a continuous-strip method for improving lubricant adhesion to one surface of such strip material and decreasing surface contact on the remaining surface during subsequent drawing and ironing operations, comprising the steps of
- providing flat rolled sheet metal in continuous-strip form,
- processing such continuous-strip to selected gage by cold rolling in continuous-strip rolling mill means including performing final cold reducing operations to impart a selected surface texture, such final cold reducing operations including the steps of
- providing roll stand means with surface contact rolls of preselected embossed finishes, and
- passing the continuous-strip through such roll stand means to impart a pattern of surface indentations on such continuous-strip surfaces,
- such surface indentations including linearly extended impressions providing a textured surface for holding lubricant on that surface of the continuous-strip to be exposed to ironing rings working on an exterior surface of a cup drawn from such continuous-strip,
- with the remaining surface of the continuous-strip flat rolled sheet metal being treated simultaneously during passage through such roll stand means to imprint surface indentations including linearly extended impressions for decreasing intimate surface contact between an ironing mandrel and such remaining surface during ironing operation on such cup.
Dependencies are inferred from the claim text.