Flat Head Dome Cup

Abstract

A method and tool are provided for selectively forming the bottom of a cup or container to reduce the volume of material in the cup or bottom. The forming blank (10) includes an elongated portion (38) and / or a truncated protrusion (20). A tool assembly configured to form the forming blank (10) including the elongated portion (38) and / or the truncated protrusion (20) and a method (1000) of forming the forming blank (10) including the elongated portion (38) and / or the truncated protrusion (22) are also provided. The forming blank (10) includes a base (12) and a depending sidewall (14). The elongated portion (38) and / or the truncated protrusion (22) are disposed on the base (12) of the forming blank, and the thickness of the elongated portion (38) and / or the truncated protrusion (22) is less than the thickness of the sidewall (14). The elongated portion (38) and / or the truncated protrusion (22) utilizes less material compared to an unformed base having approximately the same thickness as the sidewall (14).

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 15 / 382,850, filed December 19, 2016, which is incorporated herein by reference.

[0002] The disclosed concepts relate generally to containers, and more particularly to metal containers such as, for example, beer or beverage cans and food cans. The disclosed concepts also relate to cups and blanks for forming cups and containers. The disclosed concepts further relate to methods and tools for selectively forming the base of a cup or container to reduce the volume of material in the cup or base. [Background technology]

[0003] It is generally well known to draw and iron sheet metal blanks to produce thin-walled containers or can bodies for containing beverages (e.g., carbonated and non-carbonated), food, or other items. As is known, many such containers are generally cylindrical, and the embodiments discussed herein are believed to have such a shape. However, it is understood that the disclosed containers (and cups resulting from the containers) and methods for forming such containers / cups are not limited to this particular shape.

[0004] One of the initial steps in forming such a container is forming a cup. As shown in FIG. 1, the cup begins as a generally flat blank 1 cut from sheet material. The blank 1 is then drawn into a cup 2. The cup 2 is generally shorter and wider than the finished container. Thus, the cup 2 typically undergoes various additional processes to further shape it into the finished container. The cup includes a base 3 having an upper depending sidewall 4. A container body, hereafter referred to as a can body 5 (FIG. 2), is formed from the cup 1 through further processes such as, but not limited to, drawing, redrawing, and ironing. The can body 5 also includes a base 6 and a sidewall 7. The can body base 6 includes a bottom profile. That is, as used herein, the "bottom profile" is the shape of the base 3 and base 6 after forming. Typically, a beverage can body 5A has a bottom profile that slopes inwardly from an annular ridge 8 to form an inwardly protruding, generally hemispherical dome 9. Conversely, food can body 5B (shown during forming in FIG. 4E) has a generally flat bottom profile. Dome 9 is formed by a "domer" during formation of cup 2 and / or can body 5. Apparatus and tools configured to form cup 2 and / or can body 5 are shown in U.S. Patent Application Serial No. 15 / 286,954, which is incorporated by reference.

[0005] There is a constant desire in the industry to reduce the gauge, i.e., the volume of material used to form such containers. However, among the drawbacks associated with forming containers from relatively thin gauge material, the containers tend to wrinkle during redraw and doming. Most prior proposals have focused on forming various shaped bottom profiles that are intended to allow can bodies to be manufactured using metals with thinner base gauges while still being strong and therefore resistant to buckling. As used herein, "base gauge" refers to the initial thickness of the material and is not limited to the thickness of the base portion / element. Therefore, it has traditionally been desirable to maintain the thickness of the material in the dome and bottom profile to maintain or increase strength in this region of the can body, thereby avoiding wrinkles.

[0006] A tool for forming a domed cup or can body traditionally includes a curved or arcuate punch core and a die core having a corresponding curvature, and the 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 downward into the die core to form the domed cup or can body. During this forming operation, the material is drawn between the punch core and the die core. That is, to maintain the thickness of the domed portion, the material is relatively lightly clamped on both sides of the domed portion. Therefore, to maintain a desired thickness in the bottom profile, the material can move (e.g., slide) or flow toward the dome as the dome is formed. Furthermore, it is known to form a bottom profile that includes a substantially flat surface (when viewed in cross section) instead of a dome, as shown in U.S. Pat. No. 5,394,727. Such protrusions can also be formed by drawing material over a die. Known domes and protrusions are configured to generally maintain the material thickness during dome formation.

[0007] Furthermore, can bodies formed from cups with generally hemispherical domes also have drawbacks. For example, some beverage can bodies are formed by inverting, or flattening, the dome of the cup and reforming the dome on the can body. This process is illustrated in FIGS. 3A-3C and includes the steps of inverting the dome (FIGS. 3B and 3C) and reforming the dome on the can body (FIGS. 3D and 3E). The generally arcuate, or generally hemispherical, dome of the cup, as shown, is generally arcuate in cross section and defines a volume of metal that must be reformed when the cup is formed into the can body. Furthermore, it should be noted that generally arcuate domes involve a larger volume of metal compared to other shapes, such as, but not limited to, truncated domes, as shown in FIG. 5A, as discussed below. This larger volume of metal can lead to wrinkling or other defects in the metal during formation of the can body. This also applies to food can bodies when formed from cups with generally arcuate domes. Food can bodies typically have a generally flat bottom; the process for forming a food can body is shown in Figures 4A-4E. Similar to beverage can bodies, the larger volume of metal in a generally hemispherical dome, i.e., a generally arcuate dome when viewed in cross section, creates defects in the food can body when the cup is reshaped.

[0008] Therefore, there is room for improvement in containers such as beer / beverage cans and food cans, selectively formed cups and tools, and methods for providing such cups and containers. That is, a problem in the prior art is that cup or can bodies use too much material, especially in the base. Summary of the Invention

[0009] The disclosed and claimed concepts provide a formed blank including an elongated portion and / or a truncated protrusion, a tool assembly configured to form the formed blank including the elongated portion and / or the truncated protrusion, and a method of forming the formed blank including the elongated portion and / or the truncated protrusion. The formed blank includes a base and a dependent sidewall. The elongated portion and / or the truncated protrusion are disposed on the base of the formed blank, and the thickness of the elongated portion and / or the truncated protrusion is thinner than the sidewall. The elongated portion and / or the truncated protrusion utilizes less material compared to an unformed base having approximately the same thickness as the sidewall. Thus, the formed blank, the tool for forming the formed blank, and the method of forming the formed blank solve the problems discussed above. [Brief explanation of the drawings]

[0010] The present invention will be best understood from the following description of the preferred embodiment when read in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a cross-sectional view of a prior art cup. [Figure 2] FIG. 1 is a cross-sectional view of a prior art can body. [Figure 3] Figures A-E illustrate the formation of a beverage can body according to the prior art. [Figure 4] Figures A to E show the formation of a food can body according to the prior art. [Figure 5A] FIG. 1 is a cross-sectional view of a forming blank in the form of a cup. [Figure 5B] 1 is a cross-sectional view of a formed blank in the form of a can body. FIG. [Figure 6] FIG. 2 is a partial cross-sectional view showing a schematic of a tool assembly. [Figure 7] FIG. 10 is a cross-sectional view showing details of a domer configured to form a truncated projection. [Figure 8] Figures A-E illustrate the formation of a beverage can body from a cup having a flattened dome. [Figure 9] Figures A to E show the formation of a food can body from a cup having a truncated dome. [Figure 10] 1 is a flowchart of the disclosed method. DETAILED DESCRIPTION OF THE INVENTION

[0011] For example, directional terms used herein, such as clockwise, counterclockwise, left, right, up, down, above, below, and derivatives thereof, refer to the orientation of the elements illustrated in the drawings and do not limit the scope of the claims, unless expressly stated otherwise herein.

[0012] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0013] As used herein, "configured to [verb]" means that a particular element or assembly has a structure that is shaped, sized, arranged, coupled, and / or configured to perform a particular verb. For example, a member "configured to move" includes an element that is movably coupled to another element to cause the member to move, or an element that is configured to move in response to another element or assembly. Thus, as used herein, "configured to [verb]" specifies structure, not function. Furthermore, as used herein, "configured to [verb]" means that a particular element or assembly is intended to and designed to perform a particular verb. Thus, an element that is merely capable of performing a particular verb but is not intended or designed to perform a particular verb is not "configured to [verb]."

[0014] As used herein, "associated" means that elements are part of the same assembly and / or work together or interact with each other in some way. For example, an automobile has four tires and four hubcaps. While all of these elements are combined as part of the automobile, it is understood that each hubcap is "associated" with a particular tire.

[0015] As used herein, a statement that two or more parts or components are “coupled” means that the parts are joined or move together directly or indirectly, i.e., through one or more intermediate parts or components, wherever a link occurs. As used herein, “directly coupled” means that the two elements are in direct contact with each other. As used herein, “fixedly coupled” or “fixed” means that the two components are coupled so that they move as a unit while maintaining a constant orientation relative to each other. Thus, when two elements are coupled, all portions of the elements are coupled. However, a statement that a particular portion of a first element is coupled to a second element, e.g., the first end of an axle is coupled to a first wheel, means that the particular portion of the first element is located closer to the second element than other portions of the first element. Furthermore, an object resting on another object held in place only by gravity is not “coupled” to the lower object unless the upper object is substantially held in place in some other way. That is, for example, a book on a table is not coupled to the table, but a book glued to the table is coupled to the table.

[0016] As used herein, a "fastener" is a separate component configured to join two or more elements. Thus, for example, a bolt is a "fastener," but a tongue-and-groove joint is not a "fastener." That is, the tongue-and-groove element is part of the elements being joined, not a separate component.

[0017] As used herein, the phrases "removably coupled" or "temporarily coupled" mean that one component is coupled to another component in an essentially temporary manner. That is, the two components are coupled in a manner that allows for easy joining or separating of the components without damaging the components. For example, two components secured together with a limited number of easily accessible fasteners, i.e., fasteners that are not difficult to access, are "removably coupled," whereas two components welded or joined together with fasteners that are difficult to access are not "removably coupled." A "difficult to access fastener" is a fastener that requires the removal of one or more other components before accessing the fastener, and the "other components" are not, but are not limited to, access devices such as doors.

[0018] As used herein, "temporarily disposed" means that a first element or assembly rests on a second element or assembly in a manner that allows the first element / assembly to be moved without having to detach or manipulate the first element. For example, a book that simply rests on a table, i.e., is not glued or secured to the table, is "temporarily disposed" on the table.

[0019] As used herein, "operably coupled" means that several elements or assemblies, each movable between a first position and a second position or configuration, are coupled such that movement of the first element from one position / configuration to another position / configuration causes the second element to similarly move between positions / configurations. Note that a first element may also be "operably coupled" to another element, and not vice versa.

[0020] As used herein, a "coupling assembly" includes two or more couplings or coupling components. The components of a coupling or coupling assembly are generally not part of the same element or other elements. Therefore, the components of a "coupling assembly" may not be described simultaneously in the following description.

[0021] As used herein, a "coupling" or "coupling component" refers to one or more components of a coupling assembly. That is, a coupling assembly includes at least two components configured to be coupled together. It is understood that the components of a coupling assembly are compatible with one another. For example, in a coupling assembly, if one coupling component is a snap socket, the other coupling component is a snap plug, or if one coupling component is a bolt, the other coupling component is a nut.

[0022] As used herein, "corresponding" implies that two structural components are similar to one another and are sized and shaped so that they can fit together with a minimal amount of friction. Thus, an opening that "corresponds" to a member is sized slightly larger than the member so that the member can pass through the opening with a minimal amount of friction. This definition changes when two components are intended to fit "closely." In that situation, the difference between the sizes of the components becomes even smaller, thereby increasing the amount of friction. If the elements defining the opening and / or the component inserted into the opening are made of a deformable or compressible material, the opening may be slightly smaller than the component to be inserted into the opening. With respect to surfaces, shapes, and lines, two or more "corresponding" surfaces, shapes, or lines have substantially the same size, shape, and contour.

[0023] As used herein, a "planar body" or "planar member" is a generally thin element that includes opposing, broad, generally parallel sides, i.e., the flat surfaces of the planar member, and thinner end faces that extend between the broad, parallel sides. That is, as used herein, a "planar" element essentially has two opposing flat surfaces. The periphery, i.e., the end faces, may include a generally straight portion, as in, for example, a rectangular planar member, or may be curved, as in a disk, or may have any other shape.

[0024] As used herein, a "path of travel" or "path," when used in connection with a moving element, includes the space through which the element passes during movement. Thus, any element that moves inherently has a "path of travel" or "path."

[0025] As used herein, the phrase two or more parts or components "engage" one another means that the elements exert a force or bias on one another, either directly or through one or more intermediate elements or components. Additionally, as used herein with respect to a movable part, the movable part may "engage" another element while moving from one position to another and / or may "engage" another element once it reaches that position. Thus, statements such as "element A engages element B when element A moves to element A's first position" and "element A engages element B when element A is in element A's first position" are understood to be equivalent statements and mean either that element A engages element B while moving to element A's first position and / or that element A engages element B while in element A's first position.

[0026] As used herein, "operably engage" means "engage and move." That is, when used in reference to a first component configured to move a second, movable or rotatable component, "operably engage" means that the first component applies a force sufficient to move the second component. For example, a driver can be placed in contact with a screw. When no force is applied to the driver, the driver is simply "coupled" to the screw. When an axial force is applied to the driver, the driver is forced against the screw and "engages" the screw. However, when a rotational force is applied to the driver, the driver "operably engages" the screw and rotates it. Furthermore, in the context of electronic components, "operably engage" means that one component controls another component via a control signal or current.

[0027] As used herein, the term "unitary" refers to a component that is manufactured as a single piece or unit. That is, a component that includes pieces that are manufactured separately and then joined together as a unit is not a "unitary" component or object.

[0028] As used herein, the term "several" is intended to mean one or an integer greater than one (ie, a plurality).

[0029] As used herein, in the phrases "[x] moves between its first and second positions" or "[y] is configured to move [x] between its first and second positions," [x] is the name of an element or assembly. Furthermore, when [x] is an element or assembly that moves between positions, the pronoun "it" refers to [x], i.e., the named element or assembly that precedes the pronoun "it."

[0030] As used herein, "around," such as in phrases such as "disposed around [element, point, or axis]" or "extend around [element, point, or axis]" or "[X] degrees around [element, point, or axis]," means surrounding, extending around, or measured around. When used in connection with a measurement or in a similar manner, "about" means "approximately," i.e., within an approximate range associated with the measurement, as would be understood by one of ordinary skill in the art.

[0031] As used herein, a "radial side / surface" of a circular or cylindrical object is a side / surface that extends or surrounds the center of the object or a height line that passes through the center of the body. As used herein, an "axial side / surface" of a circular or cylindrical body is a side that extends in a plane that extends generally perpendicular to the height line that passes through the center. That is, generally, for a cylindrical soup can, the "radial side / surface" is the generally circular sidewall, and the "axial side / surface" is the top and bottom of the soup can.

[0032] As used herein, the terms "can" and "container" are used substantially interchangeably to refer to any known or suitable container configured to contain a substance (e.g., without limitation, a liquid, food, or any other suitable substance), and expressly include, but are not limited to, beverage cans, such as beer cans and juice cans, and food cans.

[0033] As used herein, "contour" means a line or surface that defines an object. That is, for example, when viewed in cross section, the surface of a three-dimensional object is simplified to two dimensions, and therefore some of the contours of the three-dimensional surface are represented by the contours of two-dimensional lines.

[0034] As used herein, "periphery" means the area at the outer edge of a defined area, surface, or contour.

[0035] As used herein, a "flat-headed protrusion" refers to a profile of the base of a cup or the base of a can body, including an "extended portion" and a generally flat portion at the distal end of the protrusion, i.e., the end of the protrusion farthest from the base. Thus, as used herein, a "flat-headed protrusion" essentially includes an extended portion and a generally flat portion. Furthermore, as used herein, the "generally flat portion" of a "flat-headed protrusion" includes both a substantially planar element and an element that includes a bead, corrugation, or similar structure configured to accept additional material in a defined area relative to a substantially planar element having the same defined area, so long as the area that includes the bead, corrugation, or similar structure has a generally flat contour across the defined area. Furthermore, as used herein, a "flat-headed protrusion" is formed and offset inward. That is, a "flat-headed protrusion" is formed by deforming material into a space partially enclosed by the base and sidewall of a can body cup, etc. Thus, the formation of an outwardly protruding bead that extends around the base does not convert the generally flat portion of the base surrounded by the bead into a "flat head protrusion" because the generally flat portion of the base surrounded by the bead is not molded or offset inwardly.

[0036] As used herein, a "flat-headed protrusion-forming profile" is a surface on a forming element, such as, but not limited to, the surface of a die, configured to form a material into a "flat-headed protrusion" as defined above. As used herein, a "die flat-headed protrusion-forming profile" is a surface on a die, configured to form a material into a "flat-headed protrusion" as defined above.

[0037] As used herein, a "frusto-domed" is a "frusto-protruding portion" that has a generally curved (or arcuate) portion and a generally flat portion when viewed in cross section. That is, a truncated dome is a dome in which a generally flat portion is located where the apex of the dome would be, i.e., a dome with a generally flat top. Furthermore, the "elongated portion" and "generally flat portion" are in a configuration selected from the group consisting of coextensive (i.e., completely overlapping), partially coextensive (i.e., partially overlapping), or separate (i.e., non-overlapping).

[0038] As used herein, a "flat-headed dome-forming profile" is a surface of a forming element, such as, but not limited to, a surface of a die, configured to form material into a "flat-headed dome" as defined above. As used herein, a "die flat-headed dome-forming profile" is a surface of a die, configured to form material into a "flat-headed dome" as defined above.

[0039] As used herein, a "stretched portion" is a portion of a material that has been formed by stretching the material. Furthermore, as used herein, a "stretched portion" is a stretched portion, not an unstretched portion that can be stretched. Accordingly, an unstretched portion that can be stretched is specifically excluded from the definition of "stretched portion." A "frustum protrusion" or "frustum dome," in exemplary embodiments, includes both an unstretched portion and the necessary "stretched portion." That is, a protrusion / dome having only an unstretched portion, i.e., lacking a "stretched portion," is specifically excluded from the definition of "frustum protrusion" or "frustum dome." Furthermore, due to the absence of a "stretched portion," protrusions formed solely by drawing, such as the protrusions disclosed in U.S. Pat. No. 5,394,727, are specifically excluded from the definition of "frustum protrusion" and "frustum dome."

[0040] As used herein, "forming blank" means the cup and the can body formed from the cup.

[0041] As used herein, "depending" means extending at an angle other than zero (0°) from another element, regardless of direction. That is, for example, a "depending" sidewall may extend generally upward from a base.

[0042] As used herein, "substantially curved" includes elements having multiple curved portions, combinations of curved and flat portions, and multiple flat portions or sections that are angled relative to each other, thereby forming a curve.

[0043] As used herein, "generally" means "in the usual manner" with respect to the modified term, as would be understood by one of ordinary skill in the art.

[0044] As used herein, "substantially" means "mostly" with respect to the term it modifies, as would be understood by one of ordinary skill in the art.

[0045] As used herein, "at" means above and near the modified term, as understood by one of ordinary skill in the art.

[0046] Typically, as shown in Figures 5A and 5B, a forming blank 10, i.e., a cup 2 or can body 5, is formed from a blank 1. That is, the blank 1 is formed by a tool assembly 100, partially shown schematically in Figure 6. As is known, the tool assembly 100 includes a first tool assembly 102 and a second tool assembly 104. At least one of the first tool assembly 102 and the second tool assembly 104 is movable and coupled to a press 106 or similar device. In the exemplary embodiment, the first tool assembly 102 includes a forming punch 108, and the second tool assembly 104 includes a forming die 110. The press 106 is configured to move the first tool assembly 102 between a first position in which the first tool assembly 102 is spaced apart from the second tool assembly 104 and a second position in which the first tool assembly 102 is immediately adjacent to the second tool assembly 104 and is minimally spaced apart. That is, as the first tool assembly 102 moves from a first position to a second position, the forming punch 108 engages and deforms the blank 1 into the forming blank 10. As is known, in one embodiment, the tool assembly 100 is supplied with a pre-cut blank 1 that will be formed into a cup 2. In another embodiment, the tool assembly 100 is supplied with a sheet of material (not shown) and cuts the blank 1 from the sheet as part of the forming operation.

[0047] The following disclosure details the formation of a cup 2 that is subsequently formed into a can body 5, as is generally known. The cup 2 and subsequent can body 5 (hereinafter collectively referred to as a forming blank 10) include a truncated protrusion 20, as shown in FIGS. 5A and 5B. However, the following disclosure first details the construction of the finished forming blank 10. That is, the forming blank 10 includes a body 11 having a base 12 and a depending sidewall 14. Furthermore, as is known, the can body base 12 includes a ridge 16 extending around the base 12. In the exemplary embodiment, the base 12 is generally circular, and therefore the depending sidewall 14 is generally cylindrical, and the ridge 16 is an annular ridge 16'. Furthermore, in the exemplary embodiment, the truncated protrusion 20 is a truncated dome 22. That is, the base 12 includes a truncated protrusion 20 that includes several generally curved portions 30 and a generally flat portion 32. Note that the cup 2 shown in Figure 5A has a single bead (unnumbered) and is for a beverage can body 5A. Conversely, the cup (unnumbered) shown in Figure 9A has two beads and is for a food can body 5B. Generally, the cup 2 for a food can body 5B has a larger diameter than the cup 2 for a beverage can body 5A, allowing for the inclusion of one more bead.

[0048] Furthermore, compared to a generally hemispherical dome, i.e., a generally arcuate dome when viewed in cross section, the truncated dome 22 has a "reduced volume." As used herein, "reduced volume" refers to a protrusion formed on the bottom of a cup, such as, but not limited to, a truncated dome, having a reduced metal volume compared to a generally hemispherical dome, i.e., a generally arcuate dome when viewed in cross section. The length of the bottom profile of the truncated dome 22 (when viewed in cross section as shown in FIG. 5A ), i.e., the length from the outer edge of the truncated dome 22 to the center of the truncated dome 22, is shorter than the length of a generally hemispherical dome. This is because the length of the generally flat portion 32 of the truncated dome 22 is shorter than the arc of the generally hemispherical dome. In other words, if the periphery (when viewed in cross section), e.g., the arc enclosed within the sidewall 14, is flattened into an approximately straight line, the length of the flattened line is shorter than the previously existing arc. Therefore, the shorter this distance, the smaller the volume of the truncated dome 22 is than a generally hemispherical dome with the same diameter.

[0049] In one exemplary embodiment not shown, there is a single curved portion 30 extending between the annular ridge 16′ and the generally flat portion 32. Furthermore, the single curved portion 30, in the exemplary embodiment, is an arcuate portion 40. As used herein, the term “arcuate portion” refers to the shape of the truncated protrusion 20 when viewed in cross section, as shown in FIG. 5A . It is understood that the curved portion 30 (or arcuate portion 40) forms a dome-like or dome-like shape when rotated about an axis in three dimensions. In the illustrated embodiment, several generally curved portions 30 include a first generally curved portion 34 and a second generally curved portion 36. The first generally curved portion 34 of a truncated dome has a first center, and the second generally curved portion 36 of a truncated dome has a second center. As used herein, the “center” of a curve means a point located approximately equidistant from all points on the curve; in the case of an arcuate line, the “center” means a point located substantially equidistant from all points on the arcuate line. In the exemplary embodiment, first generally curvilinear portion 34 and second generally curvilinear portion 36 are first generally arcuate portion 44 and second generally arcuate portion 46, respectively.

[0050] Additionally, as discussed in more detail below, a portion of the truncated protrusion 20 (or truncated dome 22) is stretched (hereinafter, "stretched portion" 38) during the forming process such that the material forming the truncated protrusion 20 or a portion of the truncated protrusion 20 is thinner than the base gauge of the raw material (i.e., the base gauge of the blank 1, which in the exemplary embodiment is also the thickness of the sidewall 14). In an exemplary embodiment, substantially all of the truncated protrusion 20 (or truncated dome 22) has a uniform thickness. That is, in one exemplary embodiment, the stretched portion 38 extends across substantially all of the curved portion 30 (34, 36) as well as the flat portion 32. In other embodiments, the stretched portion 38 extends across only a portion of the curved portion(s) 30 (34, 36) and / or the flat portion 32. Additionally, in the exemplary embodiment, the truncated protrusion 20 (or truncated dome 22) has a thickness that is approximately 0.0003 inches to 0.002 inches less than the base gauge of the stock material and / or the sidewall 14.

[0051] Generally, tools and methods for forming a cup 2 or can body 5 having an elongated dome are disclosed in U.S. patent application Ser. No. 15 / 286,954. The following disclosure details the tool assembly 100 shown in FIG. 6 and the method (FIG. 10) for forming the truncated protrusion 20 (or truncated dome 22). As discussed above, the tool assembly 100 includes a first tool assembly 102 and a second tool assembly 104 configured to form the blank 1 into the formed blank 10, i.e., the cup 2 or can body 5. It should be noted that the blank 1 has a base gauge (thickness), and after the initial forming of the formed blank 10, the base 12 and sidewalls 14 have a thickness substantially the same as the base gauge. Furthermore, in the exemplary embodiment, the tool assembly 100 is configured and does so to maintain the thickness of the sidewalls 14 substantially at the base gauge.

[0052] The first tool assembly 102 and the second tool assembly 104 are further configured to clamp the blank of material 1 at the periphery of the base 12. In the exemplary embodiment, the periphery of the base 12 is defined by the ridges 16, and therefore the first tool assembly 102 and the second tool assembly 104 are further configured to clamp the blank of material 1 at the ridges 16. The first tool assembly 102 and the second tool assembly 104 are configured to stretch a portion of the base 12, thereby thinning the stretched portion 38 of the base relative to the base gauge of material and / or the sidewall 14. As noted above, the stretched portion 38 has a substantially uniform thickness in the exemplary embodiment. Further, in the exemplary embodiment, the stretched portion 38 is coextensive with the entire base 12. To accomplish this, the forming blank 10 is moved by the forming punch 108 to the forming die 110. In this embodiment, forming punch 108 is an elongated, generally cylindrical body 112 having a cavity 114 at its distal end. Cavity 114, in one embodiment, is generally concave and has a contour that corresponds to the shape of forming surface 120, discussed below. In other embodiments, cavity 114 is generally cylindrical; that is, forming punch 108 is generally hollow.

[0053] As shown in FIG. 6 , the forming surface 120 is disposed on the forming die 110 of the second tool assembly 104. In the exemplary embodiment, the forming die 110 remains substantially stationary relative to the forming punch 108. That is, the forming punch 108 reciprocates in a generally vertical direction, and the upper surface of the forming die 110 has a convex protrusion 111 that defines the forming surface 120. The forming surface 120 includes a truncated protrusion-forming profile 122. Accordingly, the forming punch 108 is configured to move the blank of material 1 until it contacts the truncated protrusion-forming profile 122. In the exemplary embodiment, the truncated protrusion-forming profile 122 is a truncated dome-forming profile 122′.

[0054] The truncated dome-forming profile 122′ includes several generally curvilinear portions 126 and a flat portion-forming structure 128. To form the truncated dome 22 as described above, the several generally curvilinear portions 126 of the truncated dome-forming profile include a first generally curvilinear portion 130 and a second generally curvilinear portion 132. The first generally curvilinear portion 130 of the truncated dome-forming profile has a first center 134, and the second generally curvilinear portion 132 of the truncated dome-forming profile has a second center 136. Furthermore, in the exemplary embodiment, the first generally curvilinear portion 130 of the truncated dome-forming profile is a first generally arcuate portion 140, and the second generally curvilinear portion 132 of the truncated dome-forming profile is a second generally arcuate portion 142.

[0055] The flat portion forming structure 128 of the truncated dome-forming profile is, in an exemplary embodiment, not shown, substantially planar. That is, the truncated dome-forming profile 122' is substantially flat at its top. In the illustrated embodiment, the flat portion forming structure 128 of the truncated dome-forming profile is a cavity 150. That is, the truncated dome-forming profile 122' is defined by several generally curved portions 126. The flat portion forming structure of the truncated dome-forming profile is the die cavity 150. In other words, the several generally curved portions 126 extend substantially concentrically around the cavity 150.

[0056] In this configuration, the forming blank 10, and more specifically the base 12, is clamped between the first tool assembly 102 and the second tool assembly 104 as it moves toward the forming die 110. As the forming punch 108 moves the base 12 over the truncated dome-forming profile 122′, the material of the base 12 is stretched and thinned. Furthermore, the material of the base 12 is formed to the contours of the truncated dome-forming profile 122′. That is, a portion of the base 12 is formed to a first generally curved portion 130 of the truncated dome-forming profile and a second generally curved portion 132 of the truncated dome-forming profile. Furthermore, because the center of the forming die 110 is hollow (the forming punch 108 is also hollow), the center of the base 12 remains generally flat while being thinned. In the exemplary embodiment, the first tool assembly 102 and the second tool assembly 104 are configured to form the formed blank sidewalls 14 having a thickness approximately the same as the base gauge. The first tool assembly 102 and the second tool assembly 104 are also configured to form the formed blank truncated protrusions 20 having a thickness less than the formed blank sidewalls 14. In an exemplary embodiment, the first tool assembly 102 and the second tool assembly 104 are configured to form the formed blank truncated protrusions 20 having a thickness less than the formed blank sidewalls 14 by approximately 0.0003 inches to 0.002 inches.

[0057] 10 , a method of forming a formed blank with tool assembly 100 includes step 1000 of forming a blank of material 1 to include base 12 and depending sidewall 14, as described above; step 1002 of clamping blank 1 between first tool assembly 102 and second tool assembly 104 about the periphery of base 12; and step 1004 of stretching base 12, thereby thinning a portion of base 12 relative to sidewall 14 to form drawn portion 38. In an exemplary embodiment, step 1004 of stretching base 12, thereby thinning a portion of base 12 relative to sidewall 14 to form drawn portion 38, includes step 1006 of stretching the base drawn portion to have a substantially uniform thickness. Additionally, step 1004 of stretching base 12, thereby thinning a portion of base 12 relative to sidewall 14 to form drawn portion 38, includes step 1010 of forming truncated protrusion 20. In the exemplary embodiment, Step 1010 of forming the truncated protrusion 20 includes Step 1012 of forming the truncated dome 22 .

[0058] To form the truncated dome 22 described above, forming a truncated dome 1012 includes forming a dome having a first generally curvilinear portion and a second generally curvilinear portion 1020, forming the first generally curvilinear portion about a first center 1022, and forming the second generally curvilinear portion about a second center 1024. Furthermore, forming a blank 1000 of material to form the truncated dome 22 described above and include a base 12 and a depending sidewall 14 includes forming a sidewall 14 with a thickness that generally corresponds to the base gauge of the material 1030. Furthermore, stretching the base 12, thereby thinning a portion of the base 12 relative to the sidewall 14, 1004 includes forming a stretched portion 38 having a thickness that is less than the sidewall 14 of the formed blank 1032. Further, in the exemplary embodiment, step 1004 of stretching base 12, thereby thinning a portion of base 12 relative to sidewall 14, includes step 1036 of forming stretched portion 38 having a thickness that is approximately 0.0003 inches to 0.002 inches thinner than sidewall 14.

[0059] The above-described process discloses forming a blank 1 into a cup 2 having a flat-head protrusion 20. It is understood that such a cup 1 is then formed into a can body 5, either in the same equipment or the cup 2 is transported to a body manufacturer, as is known. A can body 5 produced from such a cup 2 also includes the flat-head protrusion 20. Alternatively, when forming the cup 1 into a can body 5, the thin-walled portion is reformed into a generally concave conventional dome. That is, the dome 9 does not have a generally flat portion. As used herein, a can body 5 produced from a cup 2 having a flat-head protrusion 20 is also a formed blank 10 having a flat-head protrusion 20, regardless of whether the flat-head protrusion 20 is reformed at a later stage in processing.

[0060] That is, as shown in Figures 8A-8E, a cup 2 having a flat-head protrusion 20 is formed into a beverage can body 5'. That is, as shown in Figures 8A-8C, the cup 2 is reformed by inverting the flat-head protrusion 20. During this forming process, the bottom of the cup 2 is reformed to be substantially flat. Therefore, as shown in Figures 8D and 8E, when the beverage can body 5' is reformed with the dome, the bottom of the cup 2 is formed by the domer 180 without metal escaping as in the prior art.

[0061] Similarly, Figures 9A to 9E show the formation of a food can body 5''. In this process, the cup 2 and the truncated protrusion 20 are reshaped as a substantially flat element. Since the substantially flat portion 32 is already substantially flat, the reshaped can body does not include the offset portion that is the remainder of the dome.

[0062] While specific embodiments of the present invention have been described in detail, those skilled in the art will recognize that various changes and substitutions to these details may be made in light of the overall teachings of this disclosure. Accordingly, the particular configurations disclosed are for illustrative purposes only and do not limit the scope of the invention, which is to be given the full scope of the appended claims and any and all equivalents thereof.

Claims

1. A method for forming a can body (5) from a cup (2) with a tool assembly (100), comprising: The cup (2) is a cylindrical cup (2) with a bottom that is molded into a can body (5), a body (11) including a base (12); The body (11) includes a cylindrical sidewall (14) that is attached to the base (12); The base (12) includes a truncated projection (20); the truncated projection (20) includes a stretched portion (38) and a generally flat portion (32) at the end of the truncated projection (20) furthest from the base (12); the ratio of the diameter of the generally flat portion (32) to the diameter of the sidewall (14) is about 0.2; The tool assembly (100) includes a first tool assembly (102) and a second tool assembly (104); forming (1000) a blank (1) of material to include a base (12) and said sidewalls (14); clamping (1002) the blank (1) between the first tool assembly (102) and the second tool assembly (104) at a periphery of the base (12); stretching the base (12), thereby thinning a portion of the base (12) relative to the sidewall (14) to form the stretched portion (38); Reforming the cup (2) into a can body (5); It contains The step of reforming the cup (2) into a can body (5) comprises: making the bottom of the cup (2) substantially flat; The method includes the step of forming a dome on the bottom of the cup (2) after the step of making the bottom of the cup (2) substantially flat.

2. 10. The method of claim 1, wherein stretching the base (12) to thin a portion of the base (12) relative to the sidewall (14) to form an elongated portion (38) comprises stretching the elongated portion (38) of the base (12) to have a substantially uniform thickness (1006).

3. A method as described in claim 1 or claim 2, wherein the step (1004) of stretching the base (12) and thereby thinning a portion of the base (12) relative to the side wall (14) to form a stretched portion (38) includes a step (1010) of forming the flat-headed protrusion (20).

4. The method of claim 3, wherein forming (1010) the truncated protrusion (20) comprises forming (1012) a truncated dome (22).

5. The step (1012) of forming the truncated dome (22) comprises: forming (1020) a dome (22) having a first generally curvilinear portion (130) and a second generally curvilinear portion (132); forming (1022) the first generally curvilinear portion (130) about a first center; and forming (1024) the second generally curvilinear portion (132) about a second center.

6. The cup (2) has a base gauge, forming (1000) the blank (1) of material to include the base (12) and the sidewall (14); and thinning (1004) a portion of the base (12) to form an elongated portion (38); forming the sidewall (14) (1030) having a thickness corresponding generally to the base gauge; forming the elongated portion (38) having a thickness less than the sidewall (14) of the cup (1032); 6. The method of claim 1, comprising:

7. 7. The method of claim 6, wherein forming the enlarged portion (38) having a thickness less than the sidewall (14) of the cup (1032) includes forming the enlarged portion (38) having a thickness less than the sidewall (14) by about 0.0003 to 0.002 inches (1036).

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