MXPA97003783A - Threaded aluminum packaging and manufacturing methods - Google Patents

Abstract

The present invention relates to a resealable or resealable metal container, light in weight, made of thin gauge hard tempered metal comprising a container body having a hardened and iron-lined side wall, a wall of integral lower end and a tapered neck portion with a mouth opening therein, having a diameter substantially smaller than that of the side wall, the neck portion includes threads adapted to receive a threaded closure and seal with contained in the enva

Description

THREADED ALUMINUM PACKAGING AND MANUFACTURING METHODS This invention relates to the methods for manufacturing metal containers, and in particular to the manufacture of a container having a threaded neck portion for receiving a threaded closure for sealing the contents in the container. The packages produced by this invention may have conical tops on them with threads thereon or they may have neck portions in which the threads are formed or to which a threaded sleeve is attached. The threaded portion is adapted to receive a plastic or metal closure. It is known how to form tempered, or tempered and iron lined containers from aluminum and steel for use in the packaging of beer, soft drinks, oil and other liquids and also to be used as aerosol containers for a variety of products. Most metal beer and beverage containers are adapted to be closed with relatively flat ends or ends, which are secured on the containers by double binding or the like. The lids may have break bands formed therein and have pull tabs attached to the breaker strips to facilitate the formation of the drain openings in the lids. It is also known how to provide containers with tapered upper ends on them as described in US Pat. Nos. REF: 24802 4,262,815 / 4,574,975; 4,793,510 and 4,911,323. It is further known to provide an easy opening container with a cylindrical portion of reduced diameter on this and separate, angular, thread segments on the cylindrical portion as described in US Patent No. 3,844,443. That patent also describes a method for forming such a container, which includes one or more forming operations such as tempering and iron-lined operations. U.S. Patent No. 5,293,765 discloses a method and apparatus for manufacturing aluminum containers threaded by deep tempering, deep tempering and further stretching, or extrusion, and threads laminated in a neck portion on the end of the container. The threads are formed by placing first and second thread rolling tools adjacent to the inner and outer surfaces of the container and rotating the tools against the surfaces. The patent states that the thickness of the wall of the container must be a maximum of 20% of the separation of the thread used for the container. Threaded aluminum containers typically have been made of relatively thick metal, that is, at least 0.020 inches thick. The aluminum has been typically relatively smooth to allow the formation of the threads in such a neck. An improved method is desired for forming a package having a threaded neck portion from hard, thin-gauge, tempered metal, which is preferably an aluminum alloy. Additionally, an improved metal package is desired which has a neck threaded thereon to ensure a closure on the package. A method for forming screw containers from sheet material of hard-tack aluminum alloy having a thickness of about 0.007-0.015 inches is desired. A threaded aluminum package that is capable of maintaining a positive pressure in the package in the range of 40 to 110 psi when closed with a screw closure is desired. This invention provides methods for forming screw containers from hard, thin gauge tempered metal, such as a hard tempered aluminum alloy or steel. The package made in accordance with this invention has a cylindrical portion of reduced diameter on it with threads formed in such a cylindrical portion or in a sleeve secured around the cylindrical portion. In one embodiment, the threads are formed in a conical upper part which is double edged, adhesively bonded or otherwise secured on a cylindrical container body. Alternatively, a cylindrical container body has a diameter-reduced end thereof by stretching and re-stretching or by progressive narrowing to form an integral cylindrical portion of reduced diameter in which the threads are formed or to which a metal sleeve is attached. Threaded plastic. This invention provides methods for forming hard, lightweight tempered metal packages that have threads on them to secure closures on the packages. It could be useful to provide a method for forming threaded metal containers that are lighter in weight than prior art containers. It could also be useful to provide improved metal beverage containers which are adapted to be closed with screw closures. The method of the present invention and the product of this invention are described in an exemplified manner here in relation to the drawings, in which: Figures 1-2 are vertical cross-sectional views through two packages having conical tops on they which have been formed in accordance with this invention; Figures 3 and 4 are vertical cross-sectional views through the threaded portion of the upper parts of the package of the present invention with threaded fasteners thereon; Figures 5-10 show an advance to form the rolled metal to form a conical top portion for a package according to the present invention, preparatory to forming the threads on the top; Figure 11 is an elongated vertical cross section through the conical top of Figure 10 after the threads have been formed thereon; Figures 12-14 show some alternative ribs for the discharge ports of the threaded containers of this invention; Figure 15 shows an alternative form of the container body of this invention which has a neck portion formed by progressive stretching and re-stretching with threads formed in the neck portion and a lower end wall edged on the body of the container; Figures 16 and 17 are fragmentary views of alternative embodiments of the upper neck portion of the containers of this invention with threaded sleeves secured over the neck portions; Figures 18-27 show a progressive stretching and stretching to form the rolled metal to form a threaded container body of Figure 15 according to the present invention and adapted to have a lower end wall edged on the container body; Figure 28 shows a further alternative for a threaded container of the present invention, which has been formed by narrowing with die or die the open end of an iron-fused and tempered container body and the threads formed in the upper portion of the container. the reduced portion; Figure 29 is an elongation of the left side neck portion of the package of Figure 28 showing the progressive reductions in such neck; Figure 30 is a vertical cross-sectional view through an iron-lined and tempered container body which is adapted to be tapered or die-shaped to form a threaded container body such as that shown in Figure 28; Figure 31 is a fragmentary cross-sectional view showing the narrowed portion of a narrowed container with die or die similar to the container of Figure 28 except that it has a smooth neck instead of a gradual neck portion; Figure 32 is a fragmentary cross-sectional view of a container body similar to those of Figures 28 and 31 except that it has approximately 11 separate rungs in the neck portion; Figures 33 and 34 are alternative forms of threaded container bodies in which the threads are in separate sleeves which have been doubly crimped onto the neck portions; Figures 35-37 show the progressive steps that can be employed for the double binding of a threaded sleeve on a tapered neck portion of a container or the conical top to form an assembly similar to those shown in Figures 33 and 34. Figure 38 is a cross-sectional view through an alternative form of a dome-shaped upper portion for a threaded container of this invention in which a threaded sleeve is adhesively bonded to the dome-shaped upper portion; and Figure 39 is a schematic view through another alternative embodiment of this invention in which a long neck with threads on it, is adhesively attached to a container body having a bottom end wall doubly crimped thereon. In several of the Figures, a single line was used instead of double lines in the cross section since the material is very thin to be reasonably shown as double lines. As used herein, the words "upwards", "downwards", "inwards", "outwards", "horizontal", "vertical", and the like are with reference to a container or the upper part of the container that it is placed in an upright position with its mouth opening upwards. Figure 1 shows the metal container 1 which includes a container body 4 and a threaded conical top 10 thereon which has been produced from a thin gauge metal sheet, hard tempering according to this invention. The metal in the body of the container 4 is preferably an aluminum alloy in the 3000 series and the metal in the conical top 10 is preferably an aluminum alloy in the alloys of the 3000 or 5000 series, such as for example alloy 5042 which is in an H-19 or H-39 temper, such alloys and tempers are registered by the Aluminum Association. The aluminum in the body of the container 4 has metal thicknesses that are typical for cans for beer and soft drinks tempered and lined with iron. The aluminum in the body of the container 4 has metal thicknesses that are typical for beer containers and soft drinks tempered and lined with iron. The aluminum in the conical top 10 may be approximately 0.007-0.015 inches thick, and is preferably approximately 0.0135 inches thick for a container with a diameter of 3 inches. The packages can be of a variety of heights and diameters being an example of about 3 inches in diameter, approximately 7 1/8 inches high and designed to hold approximately 20 fluid ounces. Other containers of this invention may have diameters in the range of about 2 inches to 3.25 inches and heights of about 3.50 inches to 10 inches and may contain anywhere from 7 fluid ounces to more than 32 or more liquid ounces. This invention facilitates the use of hard, thin-gauge tempered metal for manufacturing lightweight, threaded containers, which are different from the thick-bore threaded aluminum packages produced by the methods and apparatus known in the past. The metal from which the conical top 10 is formed is preferably coated, at least on its inner surface, with a protective coating such as a polymer or an epoxy to prevent corrosion of the metal and possible adverse effects on the flavor of the a container on which the upper part is secured. The coating can be applied by roller coating, spray coating (liquid or powder), electrocoating or other similar techniques. The forming process of this invention is designed to minimize the possible damage to the rolled metal and its coating during forming operations. However, in some cases, a repair liner may be applied on the inner side of the upper part 10 after it has been formed.

The conical upper portion 10 (of Figure 1) includes an outer peripheral rim 5 which is edged on the peripheral edge of the open end of a container body 4. The upper part further includes an annular groove 6 which accommodates the tools of Ribbed and facilitates the binding operation. The annular groove 6 also provides resistance to outward deformation of the metal at the top 10 when exposed to internal pressures in the range of about 40 to 110 psi, with 110 psi being the maximum pressure in the containers for beer and soft drinks carbonated The conical top 10 further includes a frusto-conical portion 7 which is also beneficial for providing resistance to contain the pressure, a flange projecting outwardly 8 below an annular flange 9, threads 11 and a curled rib 2 around the mouth of the conical top Figure 2 shows an alternative embodiment of a package 3 having a tapered threaded upper part 21 which has been made in accordance with this invention and adhesively bonded on the upper part of an iron-lined and tempered aluminum package body 12. The container body 12 has a reduced diameter portion 13 on its upper end. The conical top portion 21 is placed over such a reduced diameter portion 13 and adhesively bonded thereto. The conical upper portion 21 is otherwise essentially the same as the tapered upper portion 10 of Figure 1. The screw containers of this invention are adapted to receive and be closed and / or sealed with a metal or plastic closure as shown. in Figures 3 and 4. The closures are preferably threaded before being applied onto the containers, but laminated metal closures can also be formed on a threaded container of this invention provided any top-loading that is applied to the container during such time. Lamination forming process does not exceed the buckling strength of the container or the threaded portion of the container which is supported against such loading in the upper part via a transfer ring on the container neck. Figure 3 shows a plastic closure 14 of the type described and illustrated in U.S. Patent No. 4,938,370, assigned to HC Industries, Inc., which is secured on the conical top 10 of Figure 1. The closure 14 has a upper wall 15, an internally threaded skirt 16 and an evident tamper evident band 17 with a plurality of flexible tabs projecting inwardly 18 on the web, which are adapted to retain the web on the package when the remainder of closure 14 is unscrewed of the container. The closure 14 has a brittle connection such as connecting slots and bridges (not shown) between its skirt and the band against obvious mishandling. This brittle connection is broken when the closure is unscrewed from the threads of the container to leave the anti-theft band on the container. Alternatively, the anti-theft band may also have one or more vertical lines of weakness therein which break when the closure is removed from a container so that the band remains attached to the closure instead of remaining on the container as it is. described, for example, in U.S. Patent No. 4,720,018, assigned to HC Industries, Inc. The disclosures contained in U.S. Patent Nos. 4,720,018 and 4,938,370 are incorporated herein by reference in this application. The closure 14 preferably includes a sealing liner 19 which seals the closure on the container to retain the contents and any carbonation in the container. The coating can seal against both the upper surface and the outer lateral surface of the rib of the container 2 to provide a reliable seal. The curled rib on a container The thread of this invention is specially adapted to be formed with closing tolerances and thus provide a highly reliable seal when the container has been closed with a threaded closure. The crimped rib provides a uniform surface essentially free of folds or irregularities therein which may interfere with obtaining an effective seal between the closure and the container. Figure 4 shows a closure of metal 20 secured on a conical top 10 (Figure 1) of this invention. The closure is preferably made of aluminum alloy of series 3000 or 5000 and may be approximately 0.008-0.015 inches thick. US Patents Nos. 2, 994,449; 3,106,808; 3,127,719; 3,460,703; 3,464,576; 3,750,821 and 4,519,516 describe some metal closures of the type that could be used to close the screw containers of this invention. The closure 20 shown in Figure 4 includes an upper wall 22, a skirt 23 and an evident anti-theft band 24 at the bottom of the skirt and connected thereto by a line 25 of marks and bridges that can be broken when the closure is unscrewed. of the container. The closure 20 has threads 26 formed in its skirt 23 and is adapted to rotate or be screwed or screwed onto the container. The lower edge 27 of the anti-theft band 24 is preferably adapted to be laminated or formed under the ridge on the rib on the container to prevent the anti-theft band from being removed from the container except for the breaking of the marked line 25 and / or the breaking of a line of vertical weakening, not shown, in the band against theft. Depending on the closure design, the anti-theft band can either remain on the container or be removed with the closure when the closure is unscrewed from the container. The closure 20 includes a sealing liner 28 which is adapted to seal against the upper and outer surfaces of the rib or ridge 2 on the container. The coating 20 is either a disc-shaped coating, which is inserted into the closure or a molded coating as is known in the art. The closure 20 preferably has a plurality of ventilation slots 29 around the outer corner to purge gases from the container during the removal of the container closure as described in US Patent No. 4,007, 851. For some applications, closures may be preferred. of aluminum to seal the containers of this invention to facilitate the recycling of the containers with the closures on them. The plastic coating and the coatings on the aluminum in such closures are a minor part of the packaging and do not interfere with the recycling of the entire package. In effect, such small amounts of plastic are burned during recycling and provide useful heat energy for recycling. Aluminum closures may also be preferred for containers that are to be sterilized, pasteurized or heated during the filling process. Figures 5 to 13 show the progress of the shapes of a thin gauge hard tempered metal sheet through the production of a conical top portion according to this invention. The tools for such progress are not shown since such tools are known in the art. The present invention resides mainly in the sequence of operations to form the upper part and the percent of reductions that take such formation, and not in the specific tools. This invention is directed towards the formation of the desired shapes while minimizing the damage to the integrity of the coating and taking optimal advantage of the aluminum forming capacity. The first step in the method of this invention is to cut a round disc 30 of sheet metal and pull a low cylindrical die stamp 31 into the center of the disc. An annular flange 32 circumscribes the die forging 31. This cutting and stretching is preferably carried out in a single operation but can comprise two operations. It is important for this invention that the first reduction of the stretch in the formation of the forging die 31 does not exceed about 45%, and is preferably about 30-40% in the formation of the hard tempering aluminum alloy , thin gauge. The percent reduction is calculated by the following formula: Cutting Percentage - Cutting Diameter - Cutting Diameter - Diameter of the Forging Pattern Cutting Edge Diameter With a reduction of 40%, the forging die 31 could have a diameter that is approximately 60% of the diameter of the disc. A reduction of 30% could produce a forging stamp diameter that is approximately 70% of the disc diameter. The application of this invention to the manufacture of conical steel tops and packages may require different rates of reduction due to the different properties of the steel, for example, strength and formability, as compared to aluminum. The following steps, as shown in Figures 6-8, again stretch the forge stamp 31 to increase its height and reduce its diameter. In accordance with this invention it is important to again stretch the forge stamp 31 at least twice to form higher forging stamps 34 and 36 with progressively smaller diameters without tearing or corrugation of the metal. The optimum number of re-stretches will depend on several factors including the caliber, tempering and forming capacity of the metal, the coatings on the metal, the diameter of the conical top and the neck portion of this, and the diameter of the threaded neck to be formed. This progressive re-stretching is critical in the formation of the thin-gauge hard tempering metal to produce a reduced diameter neck portion having sufficient length and an appropriate diameter to receive a threaded closure. The reduction percent in the first re-stretching operation, hard-gauge, thin-gauge aluminum alloy should not be more than about 35% and preferably about 30% depending on the metal gauge, temper, strength, Training capacity and coatings. The reduction in the second re-stretch should not be more than about 30% and preferably about 25%. If a third reduction is desired, this should not be greater than about 25% and preferably about 18-20%. The percent reduction is based on the change in the diameter of the forging stamps 34 and 36 between the successive re-stretches. The external diameter of the flange 32 is preferably not affected by the restoring operations. It is desirable to maximize the reduction made on each re-stretch to minimize the number of re-stretch operations. On the contrary, the percent reduction should not be greater to cause tearing or corrugation of the metal during such re-stretching.

Figure 8 shows the disc 30 after the reforming step to form an angular portion of frusto-conical rib 35 on the end of the forging die 36. Figure 9 shows the article 30 after a central portion of the end wall of the Forging die 36 (Figure 10) has been removed by a cutting operation of a disc with perforation in a manner well known in the art and the cutting edge around the opening has been moved up to lengthen the length of a Forging die 36 and leaving a flange projecting upwards 37 around the opening in the forging die to become a curled or bent outward rib. Alternatively, the cutting edge of the forging die 36 can be displaced downward to later form into a curled or inwardly bent rib. In the embodiment selected for illustration, about 70-75% of the center of the final wall of the forging die 36 has been cut off and the remaining 30-25% has been moved up to form the flange 37. Figure 10 shows the article 30 after having been cut around its lower peripheral edge and reformed in a discharge mouth 39 with the frusto-conical portion 41, an annular groove 40 and a flange curvilinearly extending outwardly around the lower peripheral edge of the discharge mouth portion. The flange 42 and the slot 40 are designed to facilitate handling and joining the conical top to an open end of a container body in the same way that the ends of a typical flat container can be attached to a container body. Figure 10 further shows a curled rib 38 around the upper edge of the discharge mouth of the article. The rib 38 is shown to be curled outwards but may also curl inwards for some applications as shown in Figure 14. An outward curling could minimize the possibility that the terminal or cutting edge of the metal in the rib could enter. in contact with the contents of a container on which a conical top is secured. Outward curling would also minimize the possibility that the beverage in the container may be trapped in the rib. An inwardly curled rib can offer advantages such as training capacity, aesthetic or similar. Figure 11 is an elongated cross-sectional view of the upper portion of the conical top 30 after it has been further reformed to provide the threads 44 and on the outwardly projecting annular rib or retaining ring 46 underneath. the threads. The rib 46 has a flange portion 48 oriented downward and outwardly under which a band can be formed against evident thefts on a closure. The neck portion 49 of the mouth between the retaining ring and the frusto-conical portion 41 has a diameter similar to that of the retaining ring. In a preferred method for producing the conical top portion the neck portion 49 is formed by rolling this portion radially inward after the threads 44 have been formed. The rib 38 preferably laughs to have a relatively small diameter of about 0.050-0.080 inches to maximize the diameter of the discharge opening and avoid interference with the threads with a closure that is applied over the conical top. The diameter of the rib 38 should be in the range of about 3-7 times the thickness of the metal in the neck. Alternatively bent ribs or edges such as those shown in Figures 12, 13 and 14 can be used with this package. The rib 38 can be formed either before or after the threads 44 are formed in the neck portion. The formation of the rib before the threads are formed is preferred for some applications since the rib provides reinforcement to the neck portion to help resist any undesirable distortion of the neck during the formation of the threads. The formation of the rib before the formation of threads will help to maintain the concentricity of the threads and maintain a parallel relationship between the rib 38 and the base of the conical top 30. The threads 44 can be formed by a variety of techniques such as by means of thread rollers similar to those shown in US Pat. No. 2,409,788 for rolling threads in a bottle closure. A mandrel having threads on it is first placed on the container neck and the rollers are applied against the outer surface of the neck and rotate around the neck to move the metal radially inwardly in the threads on the mandrel. In a preferred method, the threads 44 are formed before the neck portion 49 is formed / so that the mandrel can be inserted into and removed (by screwing) through a large opening in the bottom of the conical top. The mandrel can also be collapsible to allow the removal of this from the threaded neck of the container. The threads 44 can alternatively be formed by means of a machine and tools for making threads that are similar to those available from E. W. Bliss Industries, Inc. of Chicago, Illinois or Lou-Jan Tool &; Die, Inc. of Cheshire, Connecticut. US Patent No. 5,293,765 to Nussbaum also discloses a roll forming operation in which a supporting tool or roller is placed in the mouth and another tool or roller is rotated against the outer surfaces of the mouth to form the metal between the two rollers. The threaded conical top 30 shown in Figure 11 is now ready to be edged or otherwise secured over the open end of a container body to produce packages such as the one shown in Figure 1. This can be done by the double conventional tempering. Alternatively, the cone can be formed as shown in Figure 2 which was attached to a container body. The container body is preferably an aluminum-tempered, iron-lined aluminum container body made of 3000 series aluminum alloy. The container is adapted to be filled through the mouth and a plastic or threaded metal seal sealed thereon as shown in FIG. shown in Figures 3 and 4. The rib or edge bent over the mouth opening is important for several reasons including its operation to provide a sealing surface, protection of the metal edges, reinforcement of the mouth opening and maximization of the size of the mouth opening. Various alternative rib or edge treatments may be provided within this invention to maximize the desired performance requirements including an outwardly bent edge 50 as seen in Figure 12 (it may also be bent inwardly), a flattened rib 51 as seen in FIG. Figure 13, and the inwardly curved rib 47 of Figure 14. The folded edge 50 and the flattened rib 51 allow a mouth opening larger in diameter than the curled edge 38 of Figure 11. Curled rib 38 is more thicker than the folded edge 50 or the flattened rib 51 and must therefore result in a smaller diameter of the internal surface of the rib to avoid interference with the threads of a closure that is secured on the conical top. Figures 15, 16 and 17 illustrate alternative embodiments of the screw packages produced with this invention. These packages can be formed by stretching, re-stretching, and progressing the iron lining of the sidewall as illustrated in Figures 18-27. The package 52 of Figure 15 has an integrated threaded mouth 53 on its neck portion for receiving a threaded closure (Figures 3 and 4) and has a lower end wall in the form of an inward dome 54 double-edged on the container. The containers 55 and 56 of Figures 16 and 17 are similar except that the threaded sleeves 57 and 58 are secured over the mouths of those containers. The package 55 in Figure 16 has a metal sleeve 57 on the neck portion and the container 56 in Figure 17 has a plastic sleeve 58 on the neck portion. The sleeve 57 includes an outwardly projecting, annular rib 59, an optional annular bent lip 60 and threads 61 for receiving a threaded closure. The bent lip 60 is optional for some packages for applications in which it may be desirable to support the package on the lip during transfer or on the filling line during the application of a closure on the package. The threaded sleeves shown in Figures 16 and 17 are also adapted to be used on conical tops such as those shown in Figures 1 and 2 instead of integral threads on the conical tops. The sleeve 57 is secured on the container 55 by means of a curvilinear shoulder 62 projecting outwardly which is on the sleeve. In the manufacture of the container 55, the sleeve 57 is first connected to the cylindrical neck of the container and the rim 62 is rolled or crimped outward and downward to press against the top of the sleeve to secure the sleeve against the frusto-conical neck portion. and keep the sleeve in such a position. To prevent rotation of the sleeve over the container, small teeth, or ridges, grooves or the like can be provided on the package and / or the sleeve. After curling or forming the flange 62, the metal in the flange will flow into or around such ridges or slots to lock the sleeve in a non-rotating position on the container. The sleeve can also be adhesively attached to the package to prevent relative rotation. The rim 57 provides a top surface against which a closure or closure liner can be sealed (not shown). Figure 17 shows a similar container 56 on which a plastic sleeve 58 was used in place of a metal sleeve. The plastic sleeve 58 is secured to the mouth or neck of the container in much the same manner as the metal sleeve of Figure 16 with an outwardly curved flange 63. The plastic sleeve 58 optionally includes a transfer area 45 similar to the area 60. on the sleeve 57. Figures 18-27 show the progress of forming to make a package similar to that shown in Figure 15 having an integral mouth top on it. The same sequence can be used to make the packs 55 and 56 of Figures 16 and 17 except that the separate threaded sleeves could be secured on the packs instead of forming the integral threads on the packs.

The sequence for forming a container with a mouth upper is similar to the sequence for forming a separate conical top except that the progress includes the formation of a container side wall. Again, the tools are not shown since they are the conventional tools known in the art. The invention resides mainly in the sequence of training operations, the percent reduction taken, and the particular shapes produced by the tools. The first step is to form a stretched cup 64 of the thin gauge hard temper metal sheet. The cup 64 formed therein is shown in Figure 18. The forming operation is preferably a simple ring-and-cut operation which is well known in the art. The cup 64 includes a final wall 65 and a side wall 66. The cup 64 is preferably formed of hard tempering aluminum alloy such as alloy 3004-H-19 having a thickness in the range of about 0.007-0.015 inches, and preferably about 0.0125 inches. The rolled metal may or may not be coated with a protective coating. This will depend on whether the cup is to be subsequently lined with iron to thin its sidewall and whether the coated material can survive such an iron-lined operation without significant damage to the metal or coating. For most applications, the metal should not be precoated and should instead be coated after the side wall of the cup has been lined with iron. Figure 19 shows the reformed cup 64 which has a low or deep forging die 67 formed in the center of the side wall 65. In some cases, the forging die 67 can be formed in the first disk cutting and drawing operation . As with the formation of the conical upper portion of Figures 5-11, the forging die 67 must be reformed at least two and preferably 3 or more times to produce smaller, progressively taller forging stamps, 68, 70 and 72 as seen in Figures 20-22. The forging die 72 must have sufficient length and must be of an appropriate diameter to provide sufficient metal for the threads that will be formed therein to receive a threaded closure. It is important in the practice of this invention that the first drawing operation (Figure 18) does not exceed a 45% reduction, and preferably it is a reduction of about 35-40%, and that subsequent re-stretching operations provide reductions of approximately 20-30%. The fifth reformation shown in Figure 23 reduces the diameter of the forging die and increases its height and also reshapes the projecting end 77 of the forging die to form at least two small diameter rungs in the final portion that is projects out of the forge stamp. After the forging die 74 is reformed again to have a reduced diameter end 77, (Figure 23), the cup is newly formed to provide a frusto-conical portion 76 as shown in Figure 24. A larger portion of the The circular end wall 78 of the forging stamp is then perforated or cut. The cutting edge of the perforated perforation can also be moved upwardly to form a flange projecting upwardly 75 around the opening at the end of the forging die as shown in Figure 25. The steps of forming a rib over the upper edge of the mouth and forming thread in the mouth are essentially identical to the formation of the rib and threads in the upper conical portion 10 of Figures 1-11. The rib 79 (FIG. 26) may be curled outward or inward like the ribs on the conical tops described above. The mouth shown in Figures 26 and 27 has an outwardly projecting annular rib or retaining ring 82, a downward and outwardly facing flange 80 and threads 84 formed therein very similarly to the conical top portion 10. of Figures 1 and 11.

To complete the formation of the cup 64 in a container 87, the side wall 86 of the cup 64 is ironed with thinning and elongation using techniques well known in the art. The side wall can also receive an additional stretching operation to reduce its diameter and lengthen it before being lined with iron. The tempered and iron-coated container body 87 is subsequently preferably coated to protect it against beverage or other product that can be placed in the container, and a lower end, not shown, is placed on the body of the container to form a container ready to be filled. After filling, a plastic or pre-threaded metal closure (Figures 3 and 4) is rotatably applied to the threaded mouth to seal the contents in the container. Figures 28 and 29 show another embodiment of a threaded aluminum package 90 that has been formed in accordance with this invention. This container 90 was made entirely from a piece of hard, thin tempering metal, such as aluminum alloy 3004, 3104 or 3204 H-19. The container body before being provided with a neck and threading is a typical iron-clad and tempered container body (D &I) 91 (Figure 30) except that it has an upper "thick wall" portion 92 adapted to be narrowed. in the neck portion of the container 90. The thick wall portion 92 is not so iron coated, and therefore is thicker, the lower portion 93 of the side wall. The upper portion of the thick wall 92 has more forming capacity in a neck 94 shown in Figures 23 and 29 since the thicker metal can be formed with fewer corrugations or other undesirable deformation. The thick wall portion 92 of the container body 91 preferably begins at the tangential point between the first radius 88 between the side wall and the tapered upper portion. The thick wall extends towards the upper part of the container body which is the length of the narrowed portion. A container body tempered and lined with iron (D & I) typical (Figure 30) used in this invention may have metal of approximately 0.0135 inches in the lower profile 95, a thickness of approximately 0.0055 inches in the thin wall portion 93, and a thickness of approximately 0.0075 inches in the thick wall portion 92. Such a container body may have a diameter of 3 inches and a height of approximately 7 3/8 inches to contain 20 fluid ounces or a height of approximately 8 1/2 inches to contain 30 fluid ounces. Other D & container bodies for use with this invention may have metal thicknesses of approximately 0.010 to 0.015 inches in the lower profile 95, a thickness of approximately 0.0045 to 0.0065 inches in the thin-walled portion 93, and thicknesses of approximately 0.0065 to 0.0085 in the thick wall portion 92. Such containers can have diameters of approximately 2.5 inches to 3.5 inches and heights of approximately 5 inches to 10 inches. In accordance with this invention, the iron-tempered or lined container body 91 tapers inward toward a frusto-conical upper portion 94 by a method similar to that illustrated and described in U.S. Patent No. 5,355,710, issued October 18, 1994, the description of which is incorporated as a reference in this application. To form the one-piece aluminum package 90, at least 20, and preferably 25-28 or more nip operations are required to provide a neck to an aluminum package body having a diameter of approximately 3 inches down towards a neck which is adapted to receive a 38 mm closure. To form a neck on a container body 3 inches in diameter to receive a 43 mm closure, fewer nip operations than those required for the smaller 38 mm closure may be required. The generally frusto-conical neck portion 94 preferably has a plurality of concave-convex rungs or ridges 96 in this, instead of having a straight frustaconic neck. It is believed that the 96 rungs in the neck are aesthetically pleasing and can minimize the appearance of any rebar that may form during multiple narrowing operations. This effect is produced by processing a combination of constrictions as described in US Application Serial No. 07 / 922,913 which produces a tapered and uniform taper or straight-line taper which produces a plurality of circumferential flanges. See US Pat. Nos. 4,519,232; 4,693,108 and 4,732,027. Figure 29 is a partial cross section through the narrowed upper portion 94 of the container 90 prior to the formation of the threads and the rib on such an upper portion. As seen in Fig. 29, the upper portion 94 includes a cylindrical portion 97 in which the threads 99 (Fig. 28) are to be formed and a second cylindrical portion 98 which is adapted to curl toward a rib 100 (Fig. 28). ) around the upper periphery of the container body. The left side of Figure 29 shows the increase in reduction resulting from each of the 27 tapering operations used to form the tapered portion 94 over the diameter of the container 211. It is important that in the tapering a container body made of alloy of hard tempering aluminum have gauge thicknesses of approximately 0.0135 inches, the first reduction of constriction to be less than approximately 0.090 inches of container diameter and each subsequent reduction to be less than approximately 0.055 inches of container diameter for a container of 3 inches in diameter (300) and approximately 0.050 inches for a container of 2 11/16 (211). In one example of the constriction sequence for a container of diameter 211, the first reduction is preferably about 0.087 inches and each of the subsequent reductions is about 0.049-0.051 inches. In the practice of this invention, the thickness of the metal for larger diameter packages may be thicker than for smaller diameter packages to allow for greater reductions in each narrowing operation. The narrowing of the upper end of a container body according to this invention results in a progressive thickening of the metal in the constricted portion and therefore an increase in the structural strength of the constricted portion. The first and second cylindrical portions 97 and 98 in which the threads and the rib are formed increase in thickness from an original thickness of approximately 0.0068 inches to a final thickness in a range of approximately 0.009-0.010 inches for containers of diameter 211. For 300 diameter containers, the original thick wall may be approximately 0.0075 inches and the final thickness may be approximately 0.011 inches. Figure 28 shows the upper portion of the container after the rib 100, the threads 99, the annular rib 101 and the flange 102 have been formed therein as explained above with reference to the conical top of Figure 11. Alternatively, a threaded metal or plastic sleeve similar to that shown in Figures 16 and 17 may be secured to the body of the container 90 instead of rolling the threads in the cylindrical portion 97. Figures 31 and 32 are fragmented elongations of alternative embodiments of packages 104 and 106 having tapered neck portions thereon, which are adapted to receive threaded closures in accordance with this invention. The package 104 of Figure 31 has a smooth or uniformly tapered neck 105 on this generally formed by methods and tools similar to those described in US Patent Application Serial No. 07 / 922,913, filed July 31, 1992. The package 106 of Figure 32 has a gradual neck 107 with eleven concave-convex rungs or circumferential ribs 108 therein, which have been formed by a narrowing with a matrix similar to the techniques described, for example, by US Pat. Nos. . 4,519,232; 4,693,108 and 4,732,027. It should be apparent to those skilled in the art that more or less steps could be provided in the gradual collars of Figure 32. The number of rungs, if any, is a matter of choice depending on the desired shape to be produced, the thickness of the metal, the diameter of the container, the length of the neck to be formed and the number of narrowing operations employed. The production of rungs in the tapered neck allows to increase the reduction in each rung in comparison with a uniformly gradual neck and therefore reduces the number of operations required to achieve a given number of rungs. Figures 33 and 34 are fragmentary cross-sections of further embodiments of the containers 110 and 112 of this invention in which the threaded sleeves 111 and 113 are doubly crimped on the open ends of the packages. The tapered portion of the cans may be either a tapered top portion similar to those shown in Figures 1 and 2, a stretched / stretched pack similar to that shown in Figure 15, or a narrowed pack with a matrix similar to that shown in FIG. shown in Figures 28, 31 and 32. Figures 35-39 illustrate a method and tools for edging a threaded sleeve 114 on a container body 115. A flange projecting out 116 around the open end of the body is provided. of the package 115 and an L-shaped rim 117 is provided on the lower part of the sleeve 114. The flanges 116 and 117 are interlocked by a two-step binding operation as shown in Figures 36 and 37. The overlapping rims 116 and 117 are formed in the first edging step which partially bends the ridges downwards. In the second step shown in Figure 37, an internal support roller 118 is placed in the container, and a second hemming roller 119 presses the flange 116, 117 against the internal support roller. A drag plate 120 holds the sleeve 114 in position during the binding operation. Figures 38 and 39 illustrate yet another embodiment of a threaded conical top 122 and a threaded container 124 formed in accordance with this invention. The conical top 122 has a threaded sleeve 123 adhesively attached, welded or otherwise secured in a central opening in the conical top. The container 124 has a long nose threaded mouth 125 secured in the central opening in the upper part of the container. The package 124 is formed by a stretch / stretch method similar to that illustrated in Figures 18-25 and have a lower end wall 126 edged thereon. The package could also be a narrowed D & amp; I package with matrix similar to the packages shown in Figures 28, 31, and 32. From the above description and the accompanying drawings it is noted that this invention provides several alternatives for forming packages of threaded metal to receive threaded fasteners. Each of the alternatives offers several advantages. The weight of the container metal is a key aspect in the selection of the desired alternative. The one-piece bottle or container in Figure 28 offers the lighter weight alternative. For example, 20-ounce capacity one-piece aluminum bottles (Figure 28) will have a net weight of approximately 47-48 pounds per 1000 containers. A container having an integrated threaded upper portion of Figure 15 will have a net weight of approximately 55-56 pounds per 1000 20-ounce capacity containers. The two-piece conical top portion containers of Figure 1 have a net weight of approximately 57-58 pounds per 1000 containers (20 ounces capacity), and the attached conical top container of Figure 2 has a net weight of approximately 53-54 pounds per 1000 containers (20 ounces). Containers that have separate threaded sleeves weigh approximately 7 pounds per thousand more than fully threaded containers. The packages of this invention provide a combination of advantages and features not available in any current packaging in the prior art. The packages of this invention provide a lightweight package, inexpensive, economically recyclable, resealable / rechargeable, non-brittle, crushable or crushable which is suitable for hot filling, cold filling, aseptic filling, pasteurization and sterilization and for containing internal pressures of 40-110 psi with lives shelf life due to the barrier properties of the metal. The packages of this invention include a threaded neck portion which is adapted to receive a threaded closure and meet the operating requirements to retain the closure on the threads and to provide a reliable seal between the container and the closure. The packages are specially adapted to have threads provided therein which are dimensionally accurate to meet such performance requirements. For a long time there has been a need for packaging that provides the many advantages offered by the packages of this invention. Although several examples of the embodiments and methods of the present invention have been illustrated and described, it should be appreciated that the invention can be incorporated and practiced in other ways within the scope of the following claims. For example, this invention includes forming a constricted container with slanted tabs formed therein or in a sleeve attached thereto to secure a tab lid, instead of a threaded closure, on top of the container.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (48)

1. A resellable metal container, light in weight, made of hard tempered, thin-gauge metal, characterized in that it comprises a container body having a sidewall lined and iron-lined, a bottom end wall and a neck portion having a diameter substantially smaller than that of the side wall, the neck portion includes threads adapted to receive a threaded closure and seal the contents in the container.

2. The package according to claim 1, characterized in that the neck portion is a conical upper part which is edged or adhesively bonded onto an iron-lined and tempered container body.

3. The package according to claim 1, characterized in that the threads are on a sleeve which is secured on the neck portion.

4. The package according to claim 1, characterized in that the neck portion is integrated to the side wall and a lower end wall is edged on the container.

5. The package according to claim 1, characterized in that the side wall, the lower end wall and the neck portion are integrated with each other.

6. The container in accordance with the claim 5, characterized in that the neck portion is formed with the upper portion of an iron-lined and tempered container body narrowed with matrix.

7. The container in accordance with the claim 6, characterized in that the neck portion has at least two concave-convex rungs around the neck portion.

8. The container in accordance with the claim 1, characterized in that the portion of the metal is aluminum alloy.

9. A resealable, lightweight package made of hard, thin-gauge aluminum alloy, characterized in that it comprises a watertight, iron-lined side wall, an integral bottom end wall and an integral frusto-conical neck portion having threads therein adapted to receive a threaded closure to seal the container under pressure.

10. The package according to claim 9, characterized in that the frusto-conical neck portion is formed by matrix narrowing.

11. A resealable, lightweight package made of hard tempered aluminum alloy, thin gauge, characterized in that it comprises a recessed and lined iron side wall, a lower end edged on the side wall and a generally frustoconical neck portion integrated to the side wall and having threads on the neck portion to receive a threaded closure.

12. The package according to claim 11, characterized in that it has a threaded closure secured thereon.

13. The package according to claim 12, characterized in that the closure is made of aluminum.

14. The package according to claim 12, characterized in that the closure is made of plastic.

15. A method for forming a tapered threaded upper portion for a container, characterized in that it comprises: cutting a disc of a hard tempering aluminum alloy sheet having a thickness in the range of about 0.007-0.015 inches; Stretching a low cylindrical stamp on the disk circumscribed by a peripheral rim; re-stretching the forging stamp at least twice to increase its height and reduce its diameter to form a hat-shaped preform having a closed end wall, a cylindrical side wall and a peripheral edge portion; reforming the peripheral edge portion in a flange which is adapted to be secured on a container body; remove at least a portion of the final wall; forming a curled rib around the top of the side wall; and forming threads in the side wall to ensure a threaded closure on the article.

16. The method according to claim 15, characterized in that the crimped rib is rolled out and down.

17. The method according to claim 15, characterized in that the cylindrical forging stamp is re-stretched at least three times to increase its height and reduce its diameter.

18. The method according to claim 15, characterized in that the upper edge portion of the side wall is reduced in diameter and the crimped rib is formed of such an upper edge portion of reduced diameter.

19. The method according to claim 15, characterized in that the annular rib projecting outwards is formed in the side wall below the threads.

20. The method according to claim 15, characterized in that the cylindrical side wall is formed to have an axial length of at least 0.950-0.975 inches.

21. The method according to claim 15, characterized in that the aluminum alloy is an alloy of the 3000 or 5000 series.

22. The method according to claim 15, characterized in that the conical upper part is rimmed on a container body.

23. The method in accordance with the claim 15, characterized in that the conical upper part is adhesively secured on the container body.

24. The method according to claim 15, characterized in that the cylindrical forging die is stretched to have a diameter which is at least 60% of the diameter of the disc.

25. The method according to claim 15, characterized in that the re-stretching of the forging stamp reduces its diameter in a range of 20-30%.

26. A method for forming a laminated metal container having a threaded neck portion, characterized in that it comprises: cutting a disc of a hard tempering aluminum alloy sheet having a thickness in the range of about 0.010-0.015 inches; stretching the disc in a cup having a final wall and a cylindrical side wall; drawing a cylindrical forging stamp on the end wall circumscribed by a peripheral edge portion connecting the forge stamp to the side wall; re-stretching the forging die at least twice to increase its height and reduce its diameter to form a cylindrical neck portion having a closed end wall and a side wall connected to the peripheral edge portion; remove at least a portion of the closed end wall; forming a curled rib around the top of the side wall of the cylindrical neck portion; providing threads on the side wall of the cylindrical neck portion to ensure a threaded closure thereon.

27. The method according to claim 26, characterized in that the curled rib is formed by rotating the upper edge of the side wall radially.

28. The method according to claim 26, characterized in that the cylindrical forging stamp is re-stretched at least three times to increase its height and reduce its diameter.

29. The method according to claim 26, characterized in that the upper edge portion of the side wall is reduced in diameter and the crimped rib is formed of such an upper edge portion of reduced diameter.

30. The method in accordance with the claim 26, characterized in that the annular rib projecting outwards is formed in the side wall below the threads.

31. The method in accordance with the claim 26, characterized in that it includes ironing the side wall of the cup to reduce its thickness and increase its length.

32. The method in accordance with the claim 26, characterized in that the threads are provided in a metal ring which is secured around the recessed forged stamp.

33. The method according to claim 26, characterized in that the threads are provided in a plastic ring which is secured around the recessed forge stamp.

34. The method according to claim 26, characterized in that the threads are formed in the wall of the forge stamp.

35. The method in accordance with the claim 26, characterized in that the low cylindrical forging die is stretched to have a diameter that is at least 60% of the diameter of the cup.

36. The method in accordance with the claim 26, characterized in that each re-stretching of the forging die reduces its diameter in the range of about 20 to 30%.

37. A laminated metal characterized in that it can be made by the method according to claim 26.

38. A method for forming a laminated metal container having a neck threaded thereon for receiving a threaded closure, the method is characterized in that it comprises: cutting a disc from a sheet of hard tempering aluminum alloy having a thickness in the range of approximately 0.007-0.015 inches; stretching the disc in a cup having a final wall and a cylindrical side wall; drawing a cylindrical forging stamp on the end wall circumscribed by a peripheral edge portion connecting the forge stamp to the side wall; re-stretching the forging die at least twice to increase its height and reduce its diameter to form a cylindrical neck portion having a closed end wall and a side wall connected to the peripheral edge portion; cutting at least a portion of the final wall; placing a threaded cylindrical member around the cylindrical neck portion; and rotating the upper edge portion of the side wall outwardly to form a curled peripheral rim which is on top of the cylindrical member to retain this on the neck portion.

39. The method according to claim 24, characterized in that the cylindrical forging stamp is re-stretched at least three times to increase its height and reduce its diameter.

40. The method according to claim 24, characterized in that the cylindrical threaded member is made of aluminum sheet material.

41. The method according to claim 24, characterized in that the cylindrical threaded member is made of plastic material.

42. The method according to claim 24, characterized in that the aluminum alloy is 3004 H-19, 3104 or 3204.

43. The method according to claim 24, characterized in that the forging die has a diameter in the range of about 24-45 mm.

44. A package of rolled metal, characterized in that it is formed by the method according to claim 24.

45. A method for forming a laminated metal container having a neck threaded thereon to receive a threaded closure, the method is characterized in that it comprises: providing an iron-tempered and lined container body made of hard tempering aluminum alloy having a thickness in the range of about 0.007- 0.015 inches; the container body has a side wall which includes a thicker wall portion; progressively narrowing the wall of the thick wall portion of the side wall at least 15 times to form the thick wall portion in a generally frustoconical portion; and forming means on top of the frusto-conical portion to retain a closure therein.

46. The method in accordance with the claim 45, characterized in that it includes forming a cylindrical upper portion on the upper frustoconical portion and providing threads in the cylindrical upper portion.

47. The method in accordance with the claim 45, characterized in that the thick wall portion tapers at least 20 times progressively.

48. The method according to claim 45, characterized in that the thick wall portion tapers at least 25 times.