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EP-3523065-B1 - TOOLING FOR SELECTIVELY FORMING A BLANK OF MATERIAL INTO A CONTAINER

EP3523065B1EP 3523065 B1EP3523065 B1EP 3523065B1EP-3523065-B1

Inventors

  • CARSTENS, Aaron E.
  • MCCLUNG, JAMES A.
  • RIPPLE, PAUL L.
  • MCCARTY, Patrick K.
  • BUTCHER, GREGORY A.

Dates

Publication Date
20260506
Application Date
20170831

Claims (9)

  1. Tooling (300) for selectively forming a blank of material (20) into a container (22), the container (22) including a first sidewall (124), a second sidewall (126), and a bottom portion (128) extending between the first sidewall (124) and the second sidewall (126), the tooling (300) comprising: an upper tool assembly (402A) including a forming punch (404A); a lower tool assembly (406A including a pad (408A); the upper tool assembly (402A) and the lower tool assembly (406A) include a number of clamp beads (410) formed by one or more clamp bead recesses (414) on the forming punch (404A) and one or more clamp bead projections (412) on the pad (408A); wherein the blank of material (20) is clamped between the upper tool assembly (402A) and the lower tool assembly (406A) at each clamp bead (410); wherein the upper tool assembly (402A) and the lower tool assembly (406A) are structured to stretch the bottom portion (128) which is thereby thinned relative to the first sidewall (124) and the second sidewall (126) to form a thinned preselected profile, characterized in that said lower tooling assembly (406A) includes a hybrid bias generating assembly (500) having a pressure generating assembly (510) and a mechanical bias assembly (550), wherein the hybrid bias generating assembly (500) is structured to bias the pad (408A) against the forming punch (404A) using pressure from both the pressure generating assembly (510) and the mechanical bias assembly (550) to clamp the blank of material (20) between the upper tool assembly (402A) and the lower tool assembly (406A)wherein the hybrid bias generating assembly (500) is structured to generate a total bias pressure of pressure provided by the pressure generating assembly (510) and pressure provided by the mechanical bias assembly (550), and wherein the hybrid bias generating assembly (510) is structured to change a ratio of the pressure provided by the pressure generating assembly (510) and the pressure provided by the mechanical bias assembly (550) while the blank of material (20) is clamped between the upper tool assembly (402A) and the lower tool assembly (406A).
  2. The tooling (300) of claim 1 wherein the number of clamp beads (410) are a number of progressive clamp beads (600).
  3. The tooling (300) of claim 2 wherein: the lower tool assembly (306) includes a riser assembly (515); said riser assembly (515) having a pressure surface (521); and said riser assembly (515) is operatively coupled to said pad (408A).
  4. The tooling (300) of claim 3 wherein: the hybrid bias generating assembly (500) is operatively coupled to said riser (515).
  5. The tooling (300) of claim 4 wherein the hybrid bias generating assembly (500) includes a number of hybrid components (570).
  6. The tooling (300) of claim 4 wherein the hybrid bias generating assembly (500) is an active hybrid bias generating assembly (502).
  7. The tooling (300) of claim 4 wherein: the lower tool assembly (306) includes a pressure chamber (516); the pressure generating assembly (510) is structured to pressurize the pressure chamber (516); and the mechanical bias assembly (550) includes a number of springs (552).
  8. The tooling (300) of claim 1 wherein: the lower tool assembly (306) further includes a contour (316); and wherein the contour (316) engages and stretches the bottom portion (128) to form the thinned preselected profile.
  9. The tooling (300) of claim 6 wherein the upper tool assembly (302) and the lower tool assembly (306) are structured to stretch the blank of material (20) of the container (22) at or about the dome (130) so as to have a substantially uniform thickness.

Description

BACKGROUND Field The disclosed concept relates to tooling for selectively forming a cup or bottom portion of a container to reduce the amount of material in the cup or bottom portion and to reduce the force required to form the material as well as the counter forced acting on the tooling. Background Information It is generally well known to draw and iron a sheet metal blank to make a thin walled container or can body for packaging beverages (e.g., carbonated beverages; non-carbonated beverages), food or other substances. Typically, one of the initial steps in forming such containers is to form a cup. The cup is generally shorter and wider than the finished container. Accordingly, the cups are typically subjected to a variety of additional processes that further form the cup into the finished container. As shown, for example, in Figure 1, a conventional can body 2 has thinned first and second sidewalls 4, 6 and a bottom profile 8, which includes an outwardly protruding annular ridge 10. It is understood that in the cross-sectional view the opposing first and second sidewalls 4, 6 are portions of a contiguous sidewall (which hereinafter may be identified by a single reference number, e.g., reference "4"). The bottom profile 8 slopes inwardly from the annular ridge 10 to form an inwardly projecting dome portion 12. The can body 2 is formed from a blank of material 14 (e.g., without limitation, sheet metal). There is a constant desire in the industry to reduce the gauge, and thus the amount of material used to form such containers. However, among other disadvantages associated with the formation of containers from relatively thin gauge material, is the tendency of the container to wrinkle, particularly during redrawing and doming. Prior proposals have, in large part, focused on forming bottom profiles of various shapes that were intended to be strong and, therefore, capable of resisting buckling while enabling metal having a thinner base gauge to be used to make the can body. Thus, the conventional desire has been to maintain the material thickness in the dome and bottom profile to maintain or increase strength in this area of the can body and thereby avoid wrinkling. Tooling for forming domed cups or can bodies has conventionally included a curved, convex punch core and a concave die core, such that a domed can body is formed from material (e.g., without limitation, a sheet metal blank) conveyed between the punch core and the die core. Typically, the punch core extends downwardly into the die core, forming the domed cup or can body. In order to maintain the thickness of the domed portion, the material is relatively lightly clamped on either side of the portion to be domed. That is, the material can move (e.g., slide) or flow toward the dome as it is formed in order to maintain the desired thickness in the bottom profile. Doming methods and apparatus are disclosed, for example and without limitation, in U.S. Patent Nos. 4,685,322; 4,723,433; 5,024,077; 5,154,075; 5,394,727; 5,881,593; 6,070,447; and 7,124,613. WO 2015/126401 A1, on which the preamble of independent claim 1 is based, discloses methods and apparatus for providing expanded bottoms to containers in which metal is restrained from moving inwards from a clamped region into the region being expanded. There is, therefore, room for improvement in containers such as beer/beverage cans and food cans, as well as in selectively formed cups and tooling and methods for providing such cups and containers. SUMMARY These needs and others are met by embodiments of the disclosed concept which provide tooling for selectively forming a cup or bottom portion of a container to reduce the amount of material in the cup or bottom portion. Suitably, a container comprises: a first sidewall, a second sidewall, and a bottom portion extending between the first sidewall and the second sidewall. The material of the bottom portion is stretched relative to the first sidewall and the second sidewall to form a thinned preselected profile. The thinned preselected profile may be a dome. The material of the container at or about the dome may have a substantially uniform thickness. The container may be formed from a blank of material, wherein the blank of material has a base gauge prior to being formed. After being formed, the material of the container at or about the dome may have a thickness less than the base gauge. The thickness of the material at or about the dome may be about 7.62µm (0.0003 inch) to about 76.2 µm (0.003 inch) thinner than the base gauge. That is, there is about 10% maximum thinning of aluminum material, or 25% maximum thinning for steel, at the dome. The container may be formed from a blank of material, wherein the blank of material has a preformed dome portion. According to the invention, tooling is provided for selectively forming a blank of material into a container, the tooling being as claimed in independent claim 1. Particular embodiments of the invention ar