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A method for necking an end of a metal container include effecting initial deformation, generally radially inwardly, of an axial portion to establish a necked-in generally convex transition portion and an adjacent portion disposed between the transition portion and the container end which is initial

A method for necking an end of a metal container include effecting initial deformation, generally radially inwardly, of an axial portion to establish a necked-in generally convex transition portion and an adjacent portion disposed between the transition portion and the container end which is initially generally cylindrical. Both portions are of reduced diameter with respect to the original can body diameter. Sequentially, through the series of formation steps, the portion to be necked-in is further reduced in diameter to produce an outwardly generally convex portion disposed in underlying relationship with respect to an outwardly concave portion. A generally, radially, outwardly directed flange may be established within the end section of the necked-in portion. Apparatus to perform the foregoing forming steps consists of a plurality of die means which are subjected to relative axial movement and contact and reshape the exterior of the container portion that is to be necked-in. An additional embodiment has a necked-in portion having a plurality of alternating convex and concave portions. A further embodiment has a straight angularly, inwardly oriented portion connected to the body by a radius greater than the radius of the connection to the neck. A further embodiment creates an externally threaded necked-in portion for receipt of a threaded closure. Products produced by these methods and apparatus are disclosed.

대표청구항 ▼

[ I claim:] [1.] A method of necking an end portion of a metal container comprisingprogressively effecting in a plurality of steps a generally radially inward deformation of an axial portion of said container disposed between an open end of said container and a portion maintained at its initial diam

[ I claim:] [1.] A method of necking an end portion of a metal container comprisingprogressively effecting in a plurality of steps a generally radially inward deformation of an axial portion of said container disposed between an open end of said container and a portion maintained at its initial diameter to establish a necked-in portion, adjacent said open end and a generally frustoconical transition portion between said necked-in portion and said portion retained at its original diameter,subsequently reforming said transition portion to establish at least one outwardly concave portion underlying at least one outwardly convex portion andestablishing external threads on said necked-in portion to permit a threaded closure to be secured thereto creating generally straight portions in said transition portion between said concave portion and said convex portion, said generally straight portions measured with a length of about 0.375 to 0.625 inches.