Method and apparatus for performing multiple necking operations on a container body
AssigneeBall Corporation
InventorMilton S. Hager
Life of this patent
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Abstract
Method and apparatus for performing multiple necking operations, such as by utilizing a plurality of die necking stations. In one aspect of the present invention a plurality of venting port(s) are incorporated on a necking assembly which performs a necking operation on a necked container body. In another aspect of the present invention the container body is centered with respect to a necking assembly which produces a double-neck container body configuration.
Claims21
A method for performing multiple necking operations on an upper and open end of a sidewall of a container body having an initial diameter, comprising the steps of:
- forming a first neck portion having a first neck diameter less than the initial diameter on the upper end of the container body with a first necking assembly, said forming a first neck portion step comprising exerting a radially inwardly directed force on the upper end of the container body;
- forming a second neck portion having a second neck diameter less than the first neck diameter on at least a mesial portion of the first neck portion with a second necking assembly, said forming a second neck portion step comprising exerting a radially inwardly directed force on the at least a mesial portion of the first neck portion;
- capturing a fluid in a substantially enclosed area defined by an exterior portion of a portion of the sidewall of the container body and at least part of said second necking assembly disposed radially outwardly from said container body during at least a portion of said forming a second neck portion step, said capturing step comprising causing a potential for exerting a radially inwardly directed hydraulic force on portions of the container body which are radially and mechanically unsupported and which define a portion of said enclosed space;
- and
- venting the enclosed area during said forming a second neck portion step to reduce an amount of said hydraulic force and a potential for undesired deformation of the portions of the container body which are radially and mechanically unsupported and which define a portion of said enclosed space.
An apparatus for necking an upper and open end of a sidewall of a container body, said container body having a substantially cylindrical sidewall defining a sidewall diameter, a first transition portion extending from said sidewall inwardly toward a central axis of said container body, and a first neck portion extending from a mesial end of said first transition portion substantially parallel with said sidewall and defining a first neck diameter less than said sidewall diameter, said apparatus comprising:
- a necking die having inner and outer surfaces and at least one port interconnecting said inner and outer surfaces, said inner surface comprising a substantially cylindrical sidewall supporting bore having a diameter substantially equal to said sidewall diameter and being substantially parallel with said sidewall, a substantially frustumly-shaped necking surface on an end of said sidewall supporting bore which extends inwardly toward a central axis of said necking die for exerting a radially inwardly directed force on said upper end of said container body, and a substantially cylindrical necking bore extending from an end of said necking surface defining a second neck diameter less than said first neck diameter and being substantially parallel with said sidewall;
- a substantially cylindrical punch substantially concentrically positioned within and spaced from at least said necking bore;
- and
- means for axially advancing said container body relative to and within said necking die, wherein at least part of said first neck portion is forced inwardly toward said central axis of said container body by said necking surface and is forced between said punch and said necking bore to form a second neck portion having a second neck diameter less than said first neck diameter, wherein a fluid is captured in a substantially enclosed space defined by at least an engagement between said sidewall supporting bore of said necking die and exterior portions of said sidewall of said container body disposed radially inward therefrom and including said first neck portion prior to passing between said punch and said necking bore, said fluid having a potential for exerting a radially inwardly directed hydraulic force on portions of said container body which are radially and mechanically unsupported and which define a portion of said enclosed space, wherein said at least one port vents said enclosed space to reduce an amount of said hydraulic force and a potential for undesired deformation of said portion of said container body which is radially and mechanically unsupported and which defines a portion of said enclosed space.
Dependencies are inferred from the claim text.