Method of shaping container bodies and corresponding apparatus
AssigneeImpress Group B.V.
InventorsGuy Druesne, Cornelis Verboom
Life of this patent
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Abstract
Method wherein a) a container (1, 6) is placed in a two halves mould (2) having an internal shaped wall (21), b) an internal pressure P of a fluid is build up so as to shape the skirt (12), is characterized in that an external pressure P′of a fluid is applied in an upper space (101) contiguous to an external or upper surface (100) of the open top end (10) and/or in a lower space (141) contiguous to an external or lower surface (140) of the shaped bottom end (14), so as to have, during the span of time Δt, a pressure difference ΔP|P−P′1 low enough to prevent any distortion of the shaped open top end (10) and/or the shaped bottom end (14), so as to form a shaped metallic container (1′, 6′). An apparatus for carring out the method is also disclosed.
Claims35
A method of reshaping a skirt (12) of a hollow metallic container (1, 6) to form a shaped metallic container (1′, 6′), the hollow metallic container (1, 6) having a top end (10) with an opening (11), and a bottom end (14), the method comprising the steps of:
- placing said container (1, 6) in a two halves mould (2) having an internal shaped wall (21);
- building an internal pressure P of a first fluid during a span of time Δt within said hollow container to form a cavity (15) and to expand said skirt (12) against said shaped wall (21) such that said skirt is shaped by said shaped wall, said shaped wall (21) having an internal surface (210) defining a lateral space (211);
- and
- during said building step, applying an external pressure P′ of a second fluid in any of i) an upper space (101) contiguous to an external surface (100) of said top end (10) and ii) a lower space (141) contiguous to an external surface (140) of said bottom end (14), so as to have, during said span of time Δt, a pressure difference ΔP =|P−′| wherein a distortion of a shape of said top end (10) and/or a shape of said bottom end (14) is prevented as said first pressurized fluid acts upon said skirt (12).
An apparatus, for reshaping a skirt (12) of a hollow container (1) having a bottom end (14) and a top end (10) with an opening (11), comprising:
- a mould (2) comprised of two halves, the two halves forming a lateral space (211) bounded by an internal shaped wall (21), said mould (2) and shaped wall (21) being configured to the size of said skirt (12) of said hollow container (1, 6);
- means for supplying a first fluid in a cavity (15) inside said hollow container (1, 6) with an internal pressure P such that the first fluid causes said skirt (12) to expand against said shaped wall (21);
- auxiliary means for supplying a second fluid in an upper space (101) contiguous to an external surface (100) of said top end (10) and a lower space (141) contiguous to an external surface (140) of said bottom end (14), said auxiliary means configured to supply the second fluid at an external pressure P′ such that a pressure difference ΔP=|P−′| prevents a distortion of a shape of said top end (10) and a shape of said bottom end (14), when said first pressurized fluid acts upon said skirt (12);
- and
- upper and lower means configured to prevent a pressure equalizing between said lateral space (211) and said upper and lower spaces (101, 141).
Dependencies are inferred from the claim text.