Method of pressure-ram-forming metal containers and the like
OwnerPeter Hamstra, Stuart MacEwen +1inventors
InventorsPeter Hamstra, Stuart MacEwen, Kevin Gong
Life of this patent
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Abstract
A method of forming a bottle-shaped or other contoured metal container by subjecting a hollow metal preform having a closed end to internal fluid pressure to cause the preform to expand against the wall of a die cavity defining the desired shape, and advancing a punch into the die cavity to displace and deform the closed end of the preform after expansion begins but before it is complete. The pressure-subjecting step is performed by simultaneously subjecting the preform in the die cavity to independently controllable internal and external positive fluid pressures and varying the difference between them to control strain rate.
Claims23
A method of forming a metal container of defined shape and lateral dimensions, comprising
- (a) disposing a hollow metal preform having a closed end in a die cavity laterally enclosed by a die wall defining said shape and lateral dimensions, with a punch located at one end of the cavity and translatable into the cavity, the preform closed end being positioned in proximate facing relation to the punch and at least a portion of the preform being initially spaced inwardly from the die wall;
- (b) subjecting the preform to internal fluid pressure to expand the preform outwardly into substantially full contact with the die wall, thereby to impart said defined shape and lateral dimensions to the preform, said fluid pressure exerting force, on said closed end, directed toward said one end of the cavity;
- and
- (c) after the preform begins to expand but before expansion of the preform is complete in step (b), translating the punch into the cavity to engage and displace the closed end of the preform in a direction opposite to the direction of force exerted by fluid pressure thereon, deforming the closed end of the preform.
A method of forming a metal container of defined shape and lateral dimensions, comprising
- (a) disposing a hollow metal preform having a closed end in a die cavity laterally enclosed by a die wall defining said shape and lateral dimensions, with a punch located at one end of the cavity and translatable into the cavity, the preform closed end being positioned in proximate facing relation to the punch and at least a portion of the preform being initially spaced inwardly from the die wall;
- (b) simultaneously subjecting the preform within the cavity to internal positive fluid pressure and to external positive fluid pressure less than said internal pressure such that there is a positive internal-external fluid pressure differential, while independently controlling said internal pressure and said external pressure, to expand the preform outwardly into substantially full contact with the die wall, thereby to impart said defined shape and lateral dimensions to the preform, said fluid pressure differential exerting force, on said closed end, directed toward said one end of the cavity;
- and
- (c) after the preform begins to expand but before expansion of the preform is complete in step (b), translating the punch into the cavity to engage and displace the closed end of the preform in a direction opposite to the direction of force exerted by said fluid pressure differential thereon, deforming the closed end of the preform.
Dependencies are inferred from the claim text.