Container bottom wall reforming apparatus and method

A method for reforming a preformed, profiled bottom wall of a container having a side wall extending substantially axially from the bottom wall to define an open end of the container, comprising the steps of:

• a) applying a first support in the form of a necking spindle assembly into the open end of the container, said necking spindle assembly including a necker die assembly;
• b) applying a second support to a first portion of said bottom wall;
• c) advancing the necker die assembly into necking contact with said open end to form a necked-in diameter therein;
• and
• d) moving at least one forming finger into deforming contact with a second portion of the bottom wall, as said open end is being necked, so that said second portion is deformed against the counter pressure of the second support acting on said first portion, wherein said bottom wall includes a preformed central panel, an annular outward conical or radial surface extending downwardly and inwardly from the side wall toward the central panel, and an annular resting radius connecting the conical surface to the central panel, said resting radius projecting downward from the central panel to define an annular support surface for the container, said resting radius being defined by said first portion which extends upward from the annular support surface to join the central panel and said second portion which is an outwardly concave portion extending upward from the annular support surface to join the side wall, said outwardly concave portion having a radius of curvature R, which is reformed by said at least one forming finger to have a reduced radius of curvature r, wherein r<R, by being pinched toward said first portion so that the annular resting radius and thereby the annular support surface defined by and between the first and second portions is tightened to have a reduced radius of curvature to resist unrolling when the container is pressurized with fluid to a predetermined extend for normal use, wherein a plurality of forming fingers are circumferentially spaced from each other to contact selected portions of said outwardly concave portion to thereby reform the resting radius by tightening it only at said selected portions.

A method for reforming a preformed, profiled bottom wall of a container having a side wall extending substantially axially from the bottom wall to define an open end of the container, comprising the steps of:

• a) applying a first support in the form of a necking spindle assembly into the open end of the container, said necking spindle assembly including a necker die assembly;
• b) applying a second support to a first portion of said bottom wall;
• c) advancing the necker die assembly into necking contact with said open end to form a necked-in diameter therein;
• and
• d) moving at least one forming finger into deforming contact with a second portion of the bottom wall, as said open end is being necked, so that said second portion is deformed against the counter pressure of the second support acting on said first portion, wherein said bottom wall includes a preformed central panel, an annular outward conical or radial surface extending downwardly and inwardly from the side wall toward the central panel, and an annular resting radius connecting the conical surface to the central panel, said resting radius projecting downward from the central panel to define an annular support surface for the container, said resting radius being defined by said first portion which extends upward from the annular support surface to join the central panel and said second portion which is an outwardly concave portion extending upward from the annular support surface to join the side wall, said outwardly concave portion having a radius of curvature R, which is reformed by said at least one forming finger to have a reduced radius of curvature r, wherein r<R, by being pinched toward said first portion so that the annular resting radius and thereby the annular support surface defined by and between the first and second portions is tightened to have a reduced radius of curvature to resist unrolling when the container is pressurized with fluid to a predetermined extend for normal use, comprising the further steps of:
• i) advancing the container into a location between a first turret and a base pad turret, the first turret containing the first support and the base pad turret containing the second support, said first and second supports being coaxially aligned with the longitudinal axis of the container;
• ii) holding the container bottom against the second support means by applying vacuum through a forming anvil of the second support to the underside of the raised central panel, said forming anvil engaging said first portion;
• iii) axially supporting the resting radius by contacting the annular support surface with an annular can support surface extending around the forming anvil;
• iv) radially inwardly deflecting said at least one forming finger into deforming contact with said second portion while the first portion is supported by the anvil in fixed radially inward spaced coelevational relationship to the second portion and the annular support surface is axially supported as in step iii;
• v) advancing the container, after the reforming step iv, towards the first support by raising the container support surface towards the first support;
• and
• vi) removing the container from between the turrets.

A method for reforming a preformed, profiled bottom wall of a container having a side wall extending substantially axially from the bottom wall to define an open end of the container, comprising the steps of:

• a) applying a first support into the open end of the container;
• b) applying a second support to a first portion of said bottom wall;
• and
• c) moving at least one forming finger into deforming contact with a second portion of the bottom wall so that said second portion is deformed against the counter pressure of the second support acting on said first portion,
• wherein the first support includes a necking spindle assembly mounted to a necking turret, and comprising the further step of reforming the profiled bottom wall during necking in of the container open end by contacting said open end with a die forming surface of the necking spindle assembly advancing axially towards said open end,
• wherein said bottom wall includes a preformed central panel, an annular outward conical or radial surface extending downwardly and inwardly from the side wall toward the central panel, and an annular resting radius connecting the conical surface to the central panel, said resting radius projecting downward from the central panel to define an annular support surface for the container, said resting radius being defined by said first portion which extends upward from the annular support surface to join the central panel and said second portion which is an outwardly concave portion extending upward from the annular support surface to join the side wall, said outwardly concave portion having a radius of curvature R, which is reformed by said at least one forming finger to have a reduced radius of curvature r, wherein r<R, by being pinched toward said first portion so that the curved resting radius and thereby the annular support surface defined by and between the first and second portions is tightened to have a reduced radius of curvature to resist unrolling when the container is pressurized with fluid to a predetermined extend for normal use,
• wherein said at least one forming member includes a plurality of forming fingers and wherein a plurality of forming fingers extend continuously around the bottom wall to contact substantially the entire periphery thereof.

A method for reforming a preformed, profiled bottom wall of a container having a side wall extending substantially axially from the bottom wall to define an open end of the container, comprising the steps of:

• a) applying a first support into the open end of the container;
• b) applying a second support to a first portion of said bottom wall;
• and
• c) moving at least one forming finger into deforming contact with a second portion of the bottom wall so that said second portion is deformed against the counter pressure of the second support acting on said first portion,
• wherein the first support includes a necking spindle assembly mounted to a necking turret, and comprising the further step of reforming the profiled bottom wall during necking in of the container open end by contacting said open end with a die forming surface of the necking spindle assembly advancing axially towards said open end,
• wherein said bottom wall includes a preformed central panel, an annular outward conical or radial surface extending downwardly and inwardly from the side wall toward the central panel, and an annular resting radius connecting the conical surface to the central panel, said resting radius projecting downward from the central panel to define an annular support surface for the container, said resting radius being defined by said first portion which extends upward from the annular support surface to join the central panel and said second portion which is an outwardly concave portion extending upward from the annular support surface to join the side wall, said outwardly concave portion having a radius of curvature R, which is reformed by said at least one forming finger to have a reduced radius of curvature r, wherein r<R, by being pinched toward said first portion so that the curved resting radius and thereby the annular support surface defined by and between the first and second portions is tightened to have a reduced radius of curvature to resist unrolling when the container is pressurized with fluid to a predetermined extend for normal use,
• wherein said at least one forming member includes a plurality of forming fingers and wherein a plurality of forming fingers are circumferentially spaced from each other to contact selected portions of said outwardly concave portion to thereby reform the resting radius by tightening it only at said selected portions.

Apparatus for reforming a preformed, profiled bottom wall of a container having a side wall extending substantially axially from the bottom wall to define an open end of the container, comprising:

• a) a forming anvil mounted for engaging said bottom wall to support said container on said apparatus;
• and
• b) forming finger means radially inwardly movable into contact with a portion of the bottom wall to deform it against the counter pressure of the forming anvil, wherein said bottom wall includes a preformed central panel and an annular resting radius connecting the side wall to the central panel, said resting radius projecting downward from the central panel to define an annular support surface for the container, said resting radius being defined by a first portion which extends upward from the annular support surface to join the central panel and a second portion which is an outwardly concave portion extending upward from the annular support surface to join the side wall, said outwardly concave portion having a radius of curvature R, which is reformed by said at least one forming finger to have a reduced radius of curvature r, wherein r<R, by being pinched toward said first portion so that the curved resting radius and thereby the annular support surface defined by and between the first and second portions is tightened to have a reduced radius of curvature to resist unrolling when the container is pressurized with fluid to a predetermined extend for normal use, further comprising means, engageable with the annular support surface, for supporting the container at a first axial position where reforming occurs and at a second axial portion where the container is stripped from the apparatus, further comprising control means for coordinating radial movement of the forming finger means with axial movement of the container supporting means, wherein said control means includes actuating ring means, mounted for axial movement within an outer housing, and including a first camming surface engageable with a cam follower surface on the forming finger means, whereby axial movement of the actuating ring means causes the first camming surface to press against the cam follower surface and thereby radially inwardly deflect said forming finger means into reforming contact with the bottom wall.