Container and method for strengthening bottom of container

IS 2 129 396 T5

DESCRIPTION

Apparatus and method for reinforcing the bottom of a container.

Field of the invention

The present invention relates generally to metal container bodies of the type having a seamless side wall and a bottom formed integrally therewith. More particularly, the present invention relates to bottom contours that provide greater dome inversion pressure, that provide greater resistance to deformation when dropped, and that minimize or prevent the height increase of a container in which the beverage is subjected to pasteurization temperatures and / or extreme temperatures that are present in transportation and storage. Furthermore, the present invention relates to an apparatus and a method for providing these improved bottom contours.

Description of Related Art

There have been numerous two-piece container configurations, that is, containers having a container body with a one-piece bottom wall at one end, and an open end that is configured to have a lid attached thereto. Container manufacturers package beverages of various types in these containers made of either steel or aluminum alloys.

In the production of these container bodies, it is important that the body wall and the bottom wall of the container are as thin as possible so that the container can be sold at a competitive price. Much work has gone into thinning the wall of the body.

Along with the search for these thin-walled body structures, various bottom wall configurations have been investigated. An early attempt in finding sufficient resistance for the back wall was to make it in the form of a spherical vault. This general configuration is set forth in US Patent No. 3,760,751, issued to Dunn et al. On September 25, 1973. The bottom wall was provided with an inwardly concave dome, or bottom concave portion, which included a large part of the bottom wall area of ​​the container body. This domed configuration provides greater strength and resists deformation of the bottom wall under higher internal container pressures, with small changes in the overall geometry of the bottom wall throughout the range of depressions for which the container is designed.

The prior art featuring domed bottoms also includes US Patent No. 3,349,956, issued to PG Stephan on October 31, 1967; US Patent No. 3,693,828, issued to Kneusel et al. on September 26, 1972; US Patent No. 3,730,383, issued to Dunn et al. on May 1, 1973; US Patent No. 3,904,069, issued to Toukmanian on September 9, 1975; US Pat. No. 3,942,673, issued to Lyu et al. On March 9, 1976; US Patent No. 4,294,373, issued to Miller et al. on October 13, 1981; US Patent No. 4,834,256, issued to McMillin on May 30, 1989; US Patent No. 4,685,582, issued to Pulciani et al. on August 11, 1987; US Patent No. 4,768,672, issued to Pulciani et al. on September 6, 1988; and French Patent No. 1,514,970.

Patents showing apparatus for forming container bodies with inwardly dome bottoms and / or featuring container bodies having inwardly dome bottoms include US Patent No. 4,289,014, issued to Maeder et al. September 1981; US Patent No. 4,289,014, issued to Gombas on September 15, 1981; US Patent No. 4,341,321, issued to Gombas on July 27, 1982; US Pat. No. 4,372,143, issued to Elert et al. On February 8, 1983; US Patent No. 4,620,434, issued to Pulciani et al. on November 4, 1986; and WO91 / 11275, published August 8, 1991.

French Patent No. 1,514,970 (closest state of the art) presents a pressure bottle for delivering aerosols. The bottle is made up of an upper part 1 and a lower part 2. The lower part 2 includes a bottom 4 and a rim 5 that is connected to the side wall of the bottle as illustrated in Figure 1. French Patent No. 1,514,970 states that the configuration illustrated in Figure 1 can be obtained with proper machining. Patent WO91 / 11275 discloses reshaping an inner wall of a drawn and drawn container body to make the inner wall more vertical using a roller.

Also with respect to the aforementioned patents, Lyu et al. Present an inwardly domed bottom in which the shape of the domed bottom is ellipsoidal.

In US Patent No. 3,349,956, Stephan teaches the use of a reduced diameter annular abutment portion, with an inwardly domed bottom disposed in the middle of the reduced diameter annular abutment portion. Stephan also teaches stacking the reduced diameter annular abutment portion within the double seam top of another container.

In US Patent No. 3,693,828, Kneusel et al. Disclose a steel container body having a bottom portion that is frusto-conical in shape to provide a reduced diameter annular bearing portion, and having a bottom portion. internally domed which is disposed radially inward of the annular abutment portion.

IS 2 129 396 T5

Various bottom contours are adjusted to provide a more uniform coating of the inside bottom surface, including a reduced radius of the domed bottom.

In US Patent Nos. 4,685,582 and 4,768,672, Pulciani et al., Instead of the frustoconical part of Kneusel et al., Present a transition part between the cylindrical outer wall of the container body and the annular support part of reduced diameter, which includes an upper arcuate annular portion, which is convex with respect to the outer diameter of the container body, and a lower arcuate annular portion that is concave with respect to the outer diameter of the container body.

In US Pat. No. 4,834,256, McMillin features a transition portion between the cylindrical outer wall of the container body and the reduced diameter annular bearing portion, which is contoured to provide stable stacking for containers that have a double top. joint that is generally the same diameter as the outer cylindrical wall, as well as to provide a stable stacking for containers having double seam tops that are smaller than the cylindrical body. In this design, packages with reduced diameter tops are stacked within the annular, reduced diameter abutment portion, and packages with larger tops are stacked against this specially contoured transition portion.

In US Patent No. 4,732,292, issued March 22, 1988, Supik teaches making recesses in the bottom of a container body that extend from the bottom up. Various configurations of these starters are displayed. The recesses are said to increase the flexibility of the bottom and thus prevent cracking of the inner liners when the packages are subjected to internal fluid pressures.

In US Patent No. 4,885,924, issued December 12, 1989, which was filed in WIPO International Publication No. WO 83/02577 of August 4, 1983, Claydon et al. apparatus for radially inward rolling of the outer surface of the annular abutment portion, thereby reducing the radii of the annular abutment portion. The annular bearing portion is rolled inward to prevent inversion of the domed bottom when the container is subjected to internal fluid pressures.

Several of the prior art patents, including U.S. Patent No. 4,620,434 to Pulciani et al., Feature contours that are designed to increase the pressure at which the fluid within the container reverses the dome of the bottom of the container. container body. This pressure is called the static dome inversion pressure. In this patent, the contour of the transition portion is given so much emphasis that the radius of the domed partition, although generally specified within ranges, is not specified for the preferred embodiment.

However, it has been known that maximum values ​​of the dome inversion static pressure are obtained by increasing the dome curvature to an optimal value, and that a greater increase in the dome curvature produces a decrease in the static pressure of vault inversion.

As mentioned above, one of the problems is obtaining a maximum dome reversal pressure for a given metal thickness. However, another problem is obtaining resistance to deformation when a filled container is dropped on a hard surface.

The current industry test for drop resistance is called the cumulative drop height. As is done for the tests presented here, a filled container is dropped onto a steel plate from heights starting from 75mm (three inches) and increasing by 75mm (three inches) for each successive drop. The resistance at the drop height is then the sum of all the distances from which the container is dropped, including the height at which the dome is reversed, or partially reversed. That is, the drop height resistance is the cumulative height at which the bottom contour deforms sufficiently to prevent the container from standing firmly upright on a flat surface.

In US Patent Application 07 / 505,618, which has a common inventive entity, and which is the same assignee of the present application, it was shown that by decreasing the radius of the dome of the container body, the resistance to corrosion increases. cumulative drop height and dome inversion pressure decreases. Furthermore, in this earlier application it was shown that increasing the height of the inner wall increases the dome inversion pressure.

However, when the radius of the vault is decreased for a given vault height, the height of the interior wall decreases. Therefore, for a given vault height, an increase in the cumulative drop resistance, achieved by a decrease in the radius of the vault, results in a decrease in the height of the interior wall together with a consequent decrease in the Vault inversion pressure.

Therefore, one way to achieve a good combination of cumulative drop height and vault inversion pressure is to increase the vault height, thus allowing a reduction in vault radius while maintaining adequate wall height. . However, there are limits to which the vault height can be increased while still maintaining the standard diameter, height and volume specifications.

An additional problem in the design and manufacture of beverage containers has been keeping containers within specification after a pasteurization process, when filled beverage containers are stored at elevated ambient temperatures, and / or when exposed to sunlight. Sun.

IS 2 129 396 T5

This increase in height is caused by the unfolding of the annular bearing part when the internal pressure of the fluid on the domed part applies a downward force to the inner circumferential wall, and the inner circumferential wall applies a downward force on the part of annular support.

An increase in the height of a beverage container causes jamming of the containers in the filling and transport equipment, and irregularities in stacking.

A large number of containers are manufactured annually, and the manufacturers of the same are always looking to reduce the amount of metal used in manufacturing container bodies while maintaining the same operational characteristics.

Due to the large quantities of container bodies manufactured, a small reduction in metal thickness, even 2.5 x 10^-3 mm (one ten thousandth of an inch) would lead to a substantial reduction in material cost.

Summary of the invention

According to the present invention, an apparatus and method are provided for reshaping the lower concave portion of a drawn and drawn beverage container body. When reforming as taught herein, the container dome inversion pressure increases without increasing the thickness of the metal, without increasing the height of an interior wall surrounding the domed portion, without increasing the overall height of the dome, or without decreasing the radius of the vault.

Furthermore, in the present invention, both the greater resistance to bending of the annular support part, as well as the greater resistance to the cumulative drop height of the containers, are achieved without any increase in the metal content, and without any change in size. or general shape of the container body.

A container body that provides greater resistance to unfolding, greater dome inversion pressure, and greater resistance to cumulative drop height includes an outer cylindrical wall that is disposed around an axis of the container, a bottom that is attached to the wall. exterior and providing a bearing surface, and a lower concave portion that is disposed radially inward of the bearing surface, including a central partition or domed concave partition, and including a circumferential dome arrangement portion which disposes the central partition at a certain positional distance above the bearing surface.

In one embodiment of the present invention, the lower concave portion of the container body includes a portion thereof that is disposed at a first vertical distance above the abutment surface and at a first radial distance from the axis of the container; and the lower concave portion also includes an adjacent portion that is disposed at a greater vertical distance above the abutment surface and at a greater radial distance from the container axis than the first portion.

That is, the lower concave portion includes an adjacent portion that extends radially outward from a first portion that is closer to the bearing surface. In this configuration, this adjacent portion extends circumferentially around the body of the container, thereby providing an annular radial recess that arches out of the portion of the lower concavity that is closest to the bearing surface.

In another embodiment of the present invention, the adjacent portion of the lower concave portion is arcuate and extends for only a portion of the circumference of the lower concave portion. Preferably, a plurality of adjacent parts, and more preferably five adjacent parts, extend radially outward from a plurality of the first parts, and are interposed between respective parts of the first parts.

That is, a plurality of reinforcing parts are arranged on the inner circular wall of the lower concave part and extend circumferentially around the lower concave part or are circumferentially spaced.

The container of the present invention constitutes a container with better dome inversion static pressure without any increase in material, and without any change in dimensions that affects the interchangeability of the filling and / or packaging machinery.

In addition, the container of the present invention provides greater resistance to pressure-induced unfolding, and the resulting change in overall container height that accompanies fluid pressures present during the pasteurization process.

Furthermore, the container of the present invention provides greater resistance to the cumulative drop height without any increase in material, and without any change in dimensions that affects the interchangeability of the filling machinery, thus making possible a reduction, or elimination, of the padding that has been provided by the carton and box packaging.

In one embodiment, the apparatus of the present invention rotates, the container body remains stationary, the rollers of the apparatus move in a planetary path as the apparatus rotates, and the rollers move radially.

ES 2 129 396 T5 outwardly to deforming contact with the lower concave portion of the container body, in response to longitudinal movement of a portion of the apparatus.

The apparatus of this first embodiment of the present invention can be used as part of a machine that performs only the reshaping functions set forth herein. However, preferably, this apparatus is incorporated in a machine that performs other can-making functions. More preferably, the apparatus of this first embodiment is incorporated in a machine in which the open ends of the container bodies are tapered in first and second stages of drawing.

In another embodiment, the apparatus of the present invention remains rotatably stationary, the container body rotates, and the apparatus rollers move radially outward into deforming contact with the lower concave portion of the container body, in response to longitudinal movement of the container. a part of the apparatus.

This apparatus of the present invention may be incorporated into a separate machine for reshaping the lower concave portion of the container body. However, preferably, it is incorporated in a machine that performs other forming functions. More preferably, this embodiment of the present invention is incorporated into a machine that rotatably narrows and flanges the open end of the container body.

In a first aspect of the present invention, there is provided a method as claimed in claim

1.

In a second aspect of the present invention, there is provided an apparatus as claimed in claim 15.

Brief description of the drawings

Figure 1 is a front elevation of beverage containers that are packaged by wrapping them in shrink plastic film;

Figure 2 is a top view of the packaged beverage containers of Figure 1, taken substantially as seen from line of sight 2-2 of Figure 1;

Figure 3 is a sectional elevation of the bottom of the container body of one of the beverage containers of Figures 1 and 2, showing details that are generally common to prior art designs and embodiments of the present. invention;

Figure 4 is a sectional elevation showing, on an enlarged scale, details of the body of the container of Figure 3;

Figure 5 is a partially and slightly enlarged profile, generally made as an elevation of a section, of the outer contour of a container body of an embodiment of the present invention, wherein a plurality of parts of the inner side wall, in the form of arcuate and circumferentially spaced, they are disposed radially outward from other parts of the side wall;

Figure 6 is a bottom view of the container body of Figure 5, taken substantially as seen from line of sight 6-6 of Figure 5;

Figure 7 is a partially and slightly enlarged profile, generally made as an elevation of a section, of the lower part of the outer contour of a container body made in accordance with an embodiment of the present invention, wherein a circumferential part of the inner side wall is racially disposed outward from another circumferential part of the side wall;

Figure 8 is a bottom view of the container body of Figure 7, taken substantially as seen from line of sight 8-8 of Figure 7;

Figure 9 is a partially and considerably enlarged profile of the outer contour of a container body, practiced substantially as seen from section line 9-9 of Figure 6, showing the lower concave portion of the container body of Figures 5 and 6 in circumferential portions thereof that are not reshaped to the embodiment of Figures 5 and 6, and showing the lower concave portion of a container body prior to reforming to the container body of Figures 7 and 8;

Figure 10 is a partially and considerably enlarged profile of the outer contour of the container body of Figures 5 and 6, practiced substantially as seen from section line 10-10 of Figure 6, and showing the contour of circumferential parts of the lower concave part that have been reformed to the embodiment of Figures 5 and⁶;

Figure 11 is a partially and considerably enlarged profile of the outer contour of the container body of Figures 7 and 8, practiced substantially as seen from section line 11-11 of Figure 8, and showing the

ES 2 129 396 T5 outlines the lower concave portion that has been reshaped to the embodiment of Figures 7 and 8;

Figure 12 is a fragmentary top view of the container body of Figures 5 and 6, taken substantially as seen from line of sight 12-12 of Figure 5, and showing the effectively enlarged perimeter of the embodiment of Figures 5 and 6;

Figure 13 is a fragmentary top view of the container body of Figures 7 and 8 taken substantially as viewed from line of sight 13-13 of Figure 7, and showing the effectively enlarged perimeter of the embodiment of Figures 7 and 8;

Figure 14 is a section of an embodiment of the present invention in which the container body remains stationary while the rollers move, both racially outward, and in a planetary trajectory, to reshape the lower concave portion as shown in the Figures 7, 8 and 11; and wherein the open end of the container body narrows in a drawing operation that is coaxial, and at least partially simultaneous, with the reshaping of the lower concave portion;

Figure 15 is a section of the embodiment of Figure 14, practiced substantially the same as in Figure 14, showing the lower concave portion of the reformed container body, as shown in Figures 7, 8 and 11, in response to the racially outward movement of the rollers and the rotation of the rollers on a planetary path;

Figure 16 is an enlarged section of the reformer apparatus of Figures 14 and 15, practiced substantially the same as in Figure 15, and included here to allow clear part numbering;

Figure 16A is a partial section, taken substantially as seen from section line 16A-16A, and showing that the slide blocks are guided by two guide bars;

Figure 17 is a schematic drawing showing the path of the container body in a prior art narrowing machine with which the reformer apparatus of Figures 14-16 can be used, thereby achieving an open end narrowing operation. of the container body at least partially simultaneously with the reform of the lower concave part;

Figure 18 is a section of an embodiment of the present invention in which the container body rotates while a roller moves radially outward to reshape the lower concave portion as shown in Figures 7, 8 and 11, and in where the open end of the container body is flanged and / or narrowed in a rotating operation that is coaxial with the reform of the lower concave portion;

Figure 19 is a section of the reformer apparatus of Figure 18, practiced substantially the same as in Figure 18, showing the lower concave portion of the reformed container body, as shown in Figures 7, 8 and 11, in response to rotation of the container body and radially outward movement of a roller;

Figure 20 is a partial and enlarged section of the embodiment of Figures 18 and 19, practiced substantially the same as in Figure 19, and included here to allow clear part numbering;

Figure 21 is a schematic drawing showing the path of a container body in a prior art rotary forming machine with which the embodiment of Figures 18-20 may be used, thereby flanging and / or narrowing the open end of the container body by a rotating operation that is at least partially simultaneous with the reform of the lower concave part;

Figure 22 is a section of one embodiment of the present invention, in which two rollers move radially outward in response to longitudinal movement of another part of the tool while the rollers rotate in a planetary path;

Figure 22A is a partial section of the embodiment of Figure 22, practiced substantially the same as in Figure 22, and showing the internal parts brought into positions for reshaping the lower concave portion of a container;

Figure 23 is a section of an embodiment of the present invention, in which a container body and a roller rotate at a predetermined rate of speed, and in which projections extending radially outward from the roller radially outwardly deform a plurality of parts of the lower concave portion, as shown in Figures 5, 6 and 10, in response to the transverse movement of the roller and the rotation of the container body and the roller;

Figure 24 is a front view of the embodiment of Figure 23, taken substantially as seen from line of sight 24-24, showing the outwardly extending projections of the roller;

Figure 25 is a section of an embodiment of the present invention, showing a half section in which a plurality of machining elements are in the retracted positions, and showing another half section in which the machining elements are radially moved. outward, in response to longitudinal movement

ES 2 129 396 T5 of another part of the tool, for radially outward drawing a plurality of parts of the lower concave part, as shown in Figures 5, 6 and 10;

Figure 25A is a half section of the embodiment of Figure 25, taken substantially as shown in Figure 25, and included herein to allow clear part numbering;

Figure 26 is a section of an embodiment of the present invention in which the container body rotates, and an eccentrically mounted roller is moved transversely outward in response to the rotating arrangement of a portion of the machining device by a cam;

Figure 27 is a partial front view of the embodiment of Figure 26, taken substantially as seen from line of sight 27-27, but with the revolver drum removed to show the cam, cam follower, and pivot arm. ; and Figure 28 is a schematic drawing of the concavity reformer machine that can be used with the embodiments of Figures 26 and 27, taken as viewed from line of sight 28-28 of Figure 26, but with the revolving drum. shown by dashed lines.

Description of the preferred embodiments

Referring now to Figures 1-4, these configurations are generally common to US Patents 4,685,582 and 4,768,672 to Pulciani et al., To a design manufactured by the assignee of the present invention, and to embodiments of the invention. present invention.

More particularly, in the present invention, container bodies such as those generally shown in Figures 3 and 4 become embodiments of the present invention by being made with the dimensions set forth herein, and / or by reshaping the lower concave portions thereof. as set forth here.

Referring now to Figures 1-4, a drawn and drawn beverage container 10 includes a container body 11 and a container lid 13. The container body 11 includes a bottom 15, and a generally cylindrical side wall 12 that is attached to the bottom 15, that has a first diameter Di and that is circumferentially disposed about an axis of the container, or vertical axis 14. Bottom 15 includes an annular abutment portion, or annular abutment means 16, disposed circumferentially about container axis 14, which is disposed radially inward of side wall 12 and which provides an annular abutment surface 18 which coincides with a baseline 19.

The annular bearing portion 16 includes an outer convex annular portion 20 that is preferably arcuate, and an inner convex annular portion 22, which is preferably arcuate, that is disposed radially inward of the outer convex annular portion 20, and is attached to the outer convex annular portion 20. The outer and inner convex annular portions, 20 and 22, have radii R₁ and R₂ whose centers of curvature are common. More particularly, both radii R₁ and R₂ they have centers of curvature at a point 24 and at a circle of revolution 26 of point 24. The circle of revolution 26 has a second diameter D2.

Bottom 15 includes a lower concave portion 25, and lower concave portion 25 includes an inner convex annular portion 22; an inner circumferential wall, or inner cylindrical wall 42; an inner concave annular portion 44; and a central septum, or domed concave septum 38.

An outer connector portion, or outer connector half 28, includes an upper convex annular portion 30, which is preferably arcuate, including a radius R₃ and which is attached to the side wall 12. The outer connector portion 28 also includes a concave annular portion 32 that is disposed radially inward of a line 34, or a frusto-conical surface of revolution 36, which is tangent to the outer convex annular portion. 20 and to the upper convex annular portion 30. Thus, the outer connecting means 28 joins the side wall 12 to the outer convex annular portion 20.

The domed concave partition 38 is preferably spherical in shape, but may be of any appropriate curved shape; preferably has an approximate radius of curvature, or radius of dome R₄; it is arranged radially inward of the annular bearing portion 16; and extends upwardly into the container body 11 when the container body 11 is in a vertical position.

The container body 11 also includes an inner connecting part, or inner connecting means 40, having an inner wall 42, with a height L1 extending upward with respect to the container axis 14, which may be cylindrical, or which may be frusto-conical and inclined inwards, towards the axis 14 of the container with an angle α₁. The inner connecting portion 40 also includes the inner concave annular portion 44 having a radius of curvature R₅ and connecting the inner wall 42 and the domed partition 38. Thus, the inner connecting part 40 joins the domed partition 38 to the annular abutment part 16.

The inner connecting portion 40 locates a perimeter P₀ of the vaulted partition 38 at a positional distance L₂above the baseline 19. As can be seen by inspection of figure 4, the positional distance L₂ is approximately equal to, but somewhat less than, the sum of the height L1 of the inner wall 42, the radius of curvature

IS 2 129 396 T5

R₅ of the inner concave annular part 44, the radius R₂ of the inner convex annular portion 22, and the thickness of the material in the inner convex annular portion 22. As seen by inspection, and can be calculated by trigonometry, the positional distance L₂ is less than the aforementioned sum in a function of angle α₁ and as a function of the angle a₃ with which the perimeter P₀ of the domed partition 38 is attached to the inner concave annular portion 44.

For example, if the radius R₅ of the inner concave annular portion 44 is 0.127 cm (0.050 in.), if the radius R₂ of the inner convex annular portion 22 is 0.102 cm (0.040 inches), and if the thickness of the material in the inner convex annular portion 22 is about 0.030 cm (0.012 inches), the positional distance L₂ is about, but slightly less than, 0.259 cm (0.102 inches) greater than the height Li of the inner wall 42.

Therefore, with the radii and metal thickness listed above, when the height Li of the inner wall 42 is 0.152 cm (0.060 inches), the positional distance L₂ it is around, but slightly less than, 0.041 cm (0.162 inches).

The annular bearing part 16 has an arithmetic mean diameter D₃ which takes place at the junction of the outer convex annular portion 20 and the inner convex annular portion 22. Therefore, the mean diameter D₃ and diameter D₂ of the circumference 26 are the same diameter. The radius R₄ of the dome is centered on the axis 14 of the container.

The concave annular portion 32 includes an outer circumferential wall 46 which extends upward from the outer convex annular portion 20 and outward away from the container axis at an angle α₂, and includes a lower concave annular portion 48 with a radius R₆. Furthermore, the concave annular portion 32 may include a lower portion of the upper convex annular portion 30, depending on the selected magnitudes of the angle α₂, the radius R₃ and the radius R₆.

Finally, the container body 11 includes a dome height, or height H₁ septum, measured from bearing surface 18 to vaulted septum 38, and a posterior diameter, or minor diameter D₄, of the inner wall 42. The upper convex annular portion 30 is tangent to the side wall 12 and has a center 50. The center 50 is at a height H2 above the bearing surface 18. A center 52 of the annular portion bottom concave 48 is on a diameter D₅. Center 52 is below bearing surface 18. More specifically, bearing surface 18 is at a distance H3 above center 52.

Referring now to Figures 3 and 4, in the prior art embodiment of the three Pulciani et al. Patents, the following dimensions were used: D₁ = 6.596 cm (2.597 inches); D₂, D₃ = 5.08 cm (2,000 inches); D₅ = 6 cm (2.365 inches); R₁, R₂ = 0.102 cm (0.040 inch); R₃ = 0.508 cm (0.200 inch); R₄ = 6.033 cm (2.375 inches); R₅ = 0.127 cm (0.050 inch); R₆ = 0.254 cm (0.100 inch); and α₁ = less than 5 degrees.

Referring now generally to Figures 5-11, the container bodies 11, made generally in accordance with the prior art configuration of Figures 3 and 4, may be reformed to the container bodies 62 of Figures 5, 6 , 9, 10 and 12, or they can be reformed to the container bodies 64 of Figures 7, 8, 11 and 13.

Referring now to Figures 5, 6, 9 and 10, the container body 62 includes a cylindrical side wall 12 and a bottom 66 having an annular bearing portion 16 with an annular bearing surface 18. The annular bearing surface 18 is arranged circumferentially around the axis 14 of the container, and is arranged in a circumference of revolution 26 where the outer convex annular portion 20 and the inner convex annular portion 22 meet.

Bottom 66 includes a lower concave portion 68 that is disposed radially inward of abutment surface 18 and that includes both domed concave partition 38 and a dome arrangement portion 70.

It should be understood that the outline shown in Figure 9, in addition to being representative of the circumferential portions of container body 62 that have not been reshaped, is also representative of container body 11 prior to reshaping to container body 62 or body. 64 of container.

The dome arrangement portion 70 disposes the domed concave partition 38 at the positional distance L2 above the bearing surface 18. The dome arrangement portion 70 includes the inner convex annular portion 22, an inner wall 71 and the portion annular inner concave 44.

Referring now to Figures 3 and 4, and more especially to Figure 4, prior to reshaping the container body 62 or container body 64, the container body 11 includes a dome arrangement portion 54. The dome arrangement portion 54 includes the inner convex annular portion 22, the inner wall 42, and the inner concave annular portion 44.

Referring now to Figures 9 and 10, fragmentary and enlarged profiles of the contours of the outer surface of the container body 62 of Figures 5 and 6 are shown. That is, the contours of the inner surface of the body 62 are not shown. of container.

The profile of Figure 9 is made substantially as presented by section line 9-9 of Figure 6 and shows the contour of the bottom 66 of the container body 62 in circumferential portions thereof in which the container arrangement portion 70 dome of the lower concave part 68 is not reformed.

IS 2 129 396 T5

Referring again to Figures 5 and 6, the dome arrangement portion 70 of the container body 62 includes a plurality of first parts 72 which are arcuately disposed around the circumference of the dome arrangement part 70 at a radial distance. R₀ of the container axis 14, as shown in Figure 6. The radial distance R₀ is half the inside diameter D₀ of Figures 9 and 10. The inside diameter D₀ it takes place at the junction of the inner convex annular portion 22 and the inner wall 71. That is, the inner diameter D0 is defined by the radially inward portion of the inner convex annular portion 22.

The dome arrangement part 70 also includes a plurality of circumferentially spaced adjacent parts 74, which are arcuately arranged around the dome arrangement part 70, are circumferentially spaced, are arranged at a radial distance R_r of the container axis 14 which is greater than the radial distance R0, and are arranged intermediate between respective parts of the plurality of first parts 72, as shown in Figure 6. The radial distance R_r of Figure 6 is equal to the sum of half the inside diameter D₀ and the radial distance X₁ of Figure 10.

In a preferred embodiment of Figures 5 and 6, adjacent portions 74 are 5 in number, each having total radial displacement for arc angle α₄ 30 degrees, and each has a total length L₃ 1.854 cm (0.730 in).

Referring again to Figure 9, in circumferential portions of the container body 62 of Figures 5 and 6, where the dome arrangement portion 70 is not reshaped, the mean diameter D₃ of the annular bearing portion 16 is 5.08 cm (2,000 inches) and the inside diameter D₀ of the lower concave portion 68 is 4,826 cm (1,900 inches), which is the minimum diameter of the inner convex annular portion 22. A radius R₇ of the outer contour of the outer convex annular portion 20 is 0.132 cm (0.052 inch) and an outer radius R₈ of the inner convex annular portion 22 is 0.132 cm (0.052 inch).

It should be noted that the radii R7 and R8 are on the outside of the container body 62 and, therefore, are greater than the radii R₁ and R₂ of figure 4 in the thickness of the material.

Referring now to Figure 10, in circumferential portions of the embodiments of Figures 5 and 6, where the dome arrangement portion 70 is reshaped, a radius R₉ the inner convex annular portion 22 is reduced, the inner diameter D₀ is increased to inside diameter D_R at radial distance X₁, an arcuate portion 76 of the dome arrangement portion 70 is tucked in, or radially offset outward, in a radial dimension X2, and the arithmetic mean diameter D₃ of the bearing part 16 is increased, in a radial dimension X₃, from diameter D₃ from Figure 9 to an arithmetic mean diameter D_S of Figure 10. The arcuate portion 76 is centered at a distance Y from the bearing surface 18 and includes a radius R_H.

Referring now to Figures 7, 8 and 11, container body 64 includes cylindrical side wall 12 and a bottom 78 having annular bearing portion 16 with bearing surface 18. A lower concave portion 80 of bottom 78 it is disposed radially inward of abutment surface 18 and includes both the domed concave partition 38 and a dome arrangement portion 82.

The dome arrangement portion 82 disposes the domed concave partition 38 at a positional distance L2 above the bearing surface 18, as seen in Figure 11. The dome arrangement portion 82 includes the inner convex annular portion 22, an inner wall 83, and the inner concave annular portion 44, as indicated and described in connection with Figures 3 and 4.

The dome arrangement portion 82 of the container body 64 includes a first circumferential portion 84 which is disposed around the dome arrangement portion 82 at the radial distance R_r of the container axis 14, as shown in Figures 8 and 11. The radial distance R_r is half the diameter D₀ of Figure 11 plus the radial distance X1. The diameter D0 occurs at the junction of the inner convex annular portion 22 and the inner wall 42 of Figure 4. That is, the diameter D0 is defined by the radially inward portion of the inner convex annular portion 22.

The dome arrangement portion 82 also includes a circumferential adjacent portion 86 which is disposed around the dome arrangement part 82, and which is disposed at an effective radius R_AND, from the container axis 14, which is greater than the radial distance R_r of the first part 84. The effective radius R_AND equals the sum of half the diameter D₀ and the radial dimension X₂ of Figure 11. That is, adjacent portion 86 includes arcuate portion 76; and the arcuate portion 86 is offset from the radial distance R0 in the radial dimension X2. Therefore, it is appropriate to say that the adjacent portion 86 is disposed radially outward from the first portion 84.

Referring again to Figure 9, before reforming, the mean diameter D3 of the annular bearing portion 16 of the container body 64 is 5.08 cm (2,000 inches); the inner diameter D0 of the lower concave portion 68 is 4.826 cm (1,900 inches), which is the minimum diameter of the inner convex annular portion 22; and the radii R7 and R8 of the outer and inner convex annular portions 20 and 22 are 0.132 cm (0.052 inches).

Referring now to Figure 11, the radius R₉ of the inner convex annular part 22 is reduced; diameter D₀ is increased to diameter D_R at radial distance X₁; an arcuate portion 76 of the dome arrangement portion 82 is tucked in, or offset radially outward, in the radial dimension X2; and the arithmetic mean diameter D₃ of the bearing part 16 and the bearing surface 18 of Figure 9 is increased to the diameter D_S from Figure 11

ES 2 129 396 T5 in radial distance X₃. The arcuate portion 76 is centered at the distance Y from the bearing surface 18 and includes the radius R_H.

Referring now to Figures 4,12 and 13, the domed concave partition 38 of the container body 11 of Figure 4 includes the perimeter P₀ and an effective perimeter without reforming P_AND which includes the inner concave annular portion 44. However, when the container body 11 is reformed to the container body 62 of Figures 5 and 6, the domed septum 38 includes a reformed effective perimeter P_E1 which is greater than the perimeter P_AND. Similarly, when the container body 11 of Figure 4 is reformed to the container body 64 of Figures 7 and 8, the domed partition 38 includes a reformed effective perimeter P_E2 which is also greater than the effective unreformed perimeter P_AND.

For testing, the container bodies 11 made according to the two different groups of dimensions, and generally conforming to the configuration of Figures 3 and 4, have been reshaped to container bodies 62 and 64.

Container bodies 11 made according to one group of dimensions before reforming are designated herein as container bodies B6A, and container bodies 11 made according to the other group of dimensions are designated herein as container bodies B7. Container bodies B6A and B7 include many dimensions that are the same. Furthermore, many of the dimensions of the B6A and B7 container bodies are the same as a prior art configuration of the assignee of the present invention.

Referring now to Figures 3, 4 and 9, prior to the reform, both the B6A container bodies and the B7 container bodies had the following dimensions: D₁ = 6.599 cm (2.598 inches); D₂, D₃ = 5.08 cm (2,000 inches); D₅ = 6.373 cm (2.509 inches); R₃ = 0.508 cm (0.200 inch); R₅ = 0.127 cm (0.050 inches); R₆ = 0.508 cm (0.200 inch); R₇ and R₈ = 0.132 cm (0.052 inch); H₂ = 0.94 cm (0.370 inch); H₃ = 0.02 cm (0.008 inch); already₂ = 30 degrees. Other dimensions, including R₄, H₁, and the thickness of the metal, are specified in Table 1.

The metal used for both B6A and B7 container bodies, for the tests presented here, was an aluminum alloy that is designated 3104 H19, and the test material was taken from production stock.

The radius R₄ of the dome, presented in Table 1, is the approximate dome radius of a container body 11; and the radius R₄ of the vault is different from the radius R_T of the vaulting tool. More particularly, as shown in Table 1, a tool with a radius R_T of 5.385 cm (2.12 inches) produces a container body 11 with a radius R4 of approximately 6.05 cm (2.38 inches).

This difference between the radii of curvature of the container body and the tool is true for the three patents of Pulciani et al., For the prior art embodiments of the assignee of the present invention, and also for the present invention.

Referring now to Figures 3, 5, 7 and 9, the radius R₄ of the vault would have a true radius of vault R_C close to axis 14 of the container, and a real radius of dome R_P different in perimeter P₀. Also, the radii R_C and R_P will vary according to variations in other parameters, such as height L₁ of the inner wall 71. In addition, the radius R₄ of the dome will vary in several distances between the axis 14 of the container and the perimeter P₀.

The dome radius RC will be somewhat less than the dome radius RP, because the perimeter P0 of the domed concave partition 38 will sag outward. However, the table gives the radius R₄ of the dome, and on the axis 14 of the container, the radius R4 of the dome is close to being equal to the real radius RC of the dome.

When the container bodies 11 are reformed to the container bodies 62 and 64 shown in Figures 5 and 7, the dome radii R_C and R_P, shown in Figure 3, may or may not change slightly with container bodies 11 made for various parameters and reformed for various parameters. The changed radii, due to reshaping the dome arrangement portions 70 and 82 shown in Figures 10 and 11, are designated as the actual radius R_cr vault and real radius R_pr dome for spokes near axis 14 of the container and near the perimeter P₀, respectively. However, since the difference between the radii RC and RP of the dome is small, and since the radii RC and RP of the dome change only slightly during the renovation, if they do, only the radius R4 from Figure 3 is used. in the attached Table and in the following description.

Reform of vault layout parts 70 and 82 results in increased radius R₅ in Figure 4. To show this change in radius, the radius R₅ after the reform it is designated as the radius of curvature R_5r in Figures 10 and 11 and in Table 1. As seen in Table 1, this change in radius R₅ it can be almost minimal, or quite large, depending on various parameters in the original container body 11 and / or the reform parameters.

When the variation of the radius R₅ of Figure 4 is quite large, as indicated for the container body B7 reformed to the container body 64, the reform of the container body 11 to the container body 64 extends an effective diameter DE of the central partition 38, which includes the part annular concave 44, and shown in Figure 9, up to an effective diameter D_E2, as shown in Figure 11.

Therefore, in the renovation process, an annular portion 88 of the dome arrangement portion 82, shown in Figure 11, approaches the central partition 38 and effectively becomes a part thereof.

IS 2 129 396 T5

Furthermore, especially in the process in which the reform is circumferential, as shown in Figures 7, 8 and 11, an annular portion 90 of the bottom 78, shown in Figure 9, lies outside the annular bearing surface 18 , approaches radially inward and effectively becomes a part of the dome arrangement portion 82 of Figure 11.

In Table 1, the static top inversion pressure (GDP) is in bars, the cumulative head of fall (ACA) is in centimeters, and the internal pressure (PI) at which the head of fall was tested cumulative is in bars.

The purpose of the cumulative drop height test is to determine the cumulative drop height at which a filled canister may exhibit partial or full inversion of the domed partition.

The procedure is as follows: 1) heat the product in the containers up to 32 ° C (90 degrees Fahrenheit), plus or minus 2 degrees; 2) place the tube of the drop height meter at 5 degrees from the vertical to achieve consequent drops of the container; 3) insert the container from the top of the tube, lower it to the 7.62 cm (3 inch) position and hold the container with one finger; 4) allow the container to fall freely and hit the steel base; 5) repeat the test at successively increasing heights in 7.62 cm (3 inch) increments; 6) palpate the vaulted septum for any bulging or "inversion" of the vaulted septum before testing the next height; 7) note the height at which the vault inversion occurs; 8) calculating the cumulative drop height, that is, adding each height from which a given container has been dropped, including the height at which the dome inversion occurs; and 9) average the results of 10 packages.

A check was carried out on both container bodies 11 B6A and B7 before reforming them to container bodies 62 and 64. In this control test, canister body B6A had a static dome reversal pressure of 6.7 bars (97 psi) and canister B7 had a static dome reversal pressure of 6.5 bars (95 psi). ). Furthermore, the B6A container body had a cumulative drop height resistance of 9 inches (22.9 cm) and the B7 container body had a cumulative drop height resistance of 33 inches (83.8 cm).

TABLE 1 (dimensions in cm)

<td></td><td colspan="2">Body 62 Interrupted Annular Input</td><td colspan="2">Body 64 Continuous Annular Inlet</td>

<td></td><td>B6A</td><td>B7</td><td>B6A</td><td>B7</td>

<td>R.</td><td> 6,045</td><td> 5,177</td><td> 6,045</td><td> 5,177</td>

<td>Rr</td><td> 5,385</td><td> 4,699</td><td> 5,385</td><td> 4,699</td>

<td>Rsr</td><td> —</td><td> —</td><td> 0,203</td><td> 1,130</td>

<td>H |</td><td> 0,978</td><td> 1,054</td><td> 0,978</td><td> 1,054</td>

<td>Dr</td><td> 4,953</td><td> 4,953</td><td> 5,080</td><td> 5,039</td>

<td>Ds</td><td> 5,131</td><td> 5,131</td><td> 5,210</td><td> 5,184</td>

<td>Rn</td><td> 0,076</td><td> 0,076</td><td> 0,127</td><td> 0,127</td>

<td>R9</td><td> 0,076</td><td> 0,076</td><td> 0,066</td><td> 0,066</td>

<td>Xi</td><td> 0,064</td><td> 0,064</td><td> 0,127</td><td> 0,107</td>

<td>X2</td><td> 0,137</td><td> 0,130</td><td> 0,140</td><td> 0,140</td>

<td>X3</td><td> 0,025</td><td> 0,025</td><td> 0,066</td><td> 0,053</td>

<td>Y</td><td> 0,213</td><td> 0,218</td><td> 0,193</td><td> 0,234</td>

<td>thickness</td><td> 0,0295</td><td> 0,3</td><td> 0,0295</td><td> 0,3</td>

<td>PI</td><td> 4</td><td> 4,1</td><td> 4</td><td> 4,1</td>

<td>GDP</td><td> 7,65</td><td> 8,27</td><td> 8,34</td><td> 8,69</td>

<td>HERE</td><td> 27,4</td><td> 76,2</td><td> 45,4</td><td> 152,4</td>

IS 2 129 396 T5

Referring now to Table 1, when container bodies B6A were reformed to container bodies 62, which have a plurality of circumferentially spaced adjacent portions 74 that are radially outwardly offset, the static reversal pressure of the dome increased from 6.7 bars (97 psi) to 7.65 bars (111 psi), and the cumulative drop height strength increased from 22.9 cm (9 inches) to 27.4 cm (10.8 inches).

When the B7 container bodies were reformed to the container bodies 62, the static reversal pressure of the dome increased from 6.5 bars (95 psi) to 8.27 bars (120 psi), and the resistance at the height of Cumulative drop decreased from 83.8 cm (33 inches) to 76.2 cm (30 inches).

When the B6A container bodies were reformed to the container bodies 64, which have a circumferential adjacent portion 86 that is offset radially outward from a first circumferential portion 84, the static reversal pressure of the canopy increased by 6.7 bars ( 97 psi) to 8.34 bars (121 psi), and the cumulative drop height strength increased from 22.9 cm (9 inches) to 45.7 cm (18 inches).

Finally, when the B7 container bodies were reformed to container bodies 64, the static reversal pressure of the dome increased from 6.5 bars (95 psi) to 8.69 bars (126 psi), and the resistance to Cumulative drop height increased from 83.8 cm (33 inches) to 152.4 cm (60 inches).

Thus, container bodies B6A and B7 reformed to container bodies 62 of Figures 5 and 6 showed an improvement in dome inversion static pressure of 14.4 percent and 26.3 percent, respectively. The B6A and B7 container bodies reformed to 62 bodies showed a cumulative drop height strength improvement of 20 percent in the case of the B6A container body, but showed a 10 percent decrease in the case of the B6A container body. container B7.

In addition, container bodies B6A and B7 reformed to container bodies 64 of Figures 7 and 8 showed an improvement in the static reversal pressure of the dome of 24.7 percent and 32.6 percent, respectively. Container bodies B6A and B7 reformed to container bodies 64 showed an improvement in cumulative drop height strength of 100 percent in the case of the B6A container body, and an 81.8 percent increase in the case container body B7.

Therefore, the present invention provides extraordinary increases in both dome inversion static pressure and cumulative drop height resistance, without increasing the size of the container body; without significantly reducing the volume of the fluid in the body of the container, as would occur by increasing the height L₁of the inner wall 71 or 83, or considerably decreasing the radius R₄ vault of the vaulted concave partition 38 of FIG. 3; and without increasing the thickness of the metal.

Although the reform of container bodies B7 to container bodies 62 did not show an increase in cumulative drop height strength, this is believed to be due to two factors. One factor is that the reformation of container bodies 11 to container bodies 62 and 64 was accomplished without the aid of suitable tools. Therefore, the test samples were not in accordance with a production quality. Another factor is that the reform of container bodies B7 to container bodies 64 resulted in a radial distance X₁ greater than that produced by the reform of container bodies B7 to container bodies 62.

However, the fact remains that the reform of the B6A container bodies to the container bodies 64 provided a substantial increase in both the static dome reversal pressure and the cumulative drop height resistance.

It is believed that further testing will uncover parameters that would provide additional increases in both the vault reversal static pressure and cumulative drop height resistance.

As the present invention provides a substantial increase in dome inversion static pressure and, with some parameters, a substantial increase in cumulative drop height resistance, it is believed that the present invention, when used with lower radii R4 of vault, or with central partition configurations other than spherical, would provide even better combinations of static top reversal pressures and cumulative drop height resistances than discussed here.

From general engineering knowledge, it is obvious that a dome radius R4 that is too large would reduce the dome inversion static pressure. Furthermore, it has been known that too small a dome radius R4 would also reduce the dome inversion static pressure, even though smaller dome radii R4 would have increased the dome inversion static pressure.

Although it is certainly not known, it appears that lower values ​​of radii R₄ The dome forces applied forces on the inner wall 42 that were concentrated more directly downward against the inner convex annular portion 22, thereby causing the unfolding of the inner convex annular portion 22 and the failure of the container body 11.

In contrast, a larger dome radius R4 would tend to flatten when under pressure. That is, as a vault that was initially flatter would flatten more due to pressure, expand radially and

ES 2 129 396 T5 would apply a radially outward force to the upper part of the inner wall 42, thereby tending to prevent unfolding of the inner convex annular portion 22.

However, a radius R₄ A larger dome would have insufficient curvature to withstand internal pressures, thereby causing the dome to reverse at pressures that are too low to meet the requirements of beverage manufacturers.

By reforming the inner wall 42 of the container body 11 to the inner wall 71 of the container body 62, or by reforming the inner wall 42 to the inner wall 83 of the container body 64, the present invention achieves increases in the static reversal pressures of the vault. This extraordinary increase in the static inversion pressures of the vault is achieved by reducing the force that tends to unfold the inner convex annular part 22.

More specifically, as seen in Figure 11, in the case of the container body 64 where the adjacent portion 86 of the dome arrangement portion 82 is circumferential, an effective diameter, which is the inner diameter D₀ of the lower concave part 25 of the container body 11, is increased to a diameter D_E2. Container body 64 has effective perimeter P_E2, as shown in Figure 13.

Now, as seen in Figure 10, which shows circumferentially spaced adjacent portions 74 that are offset outward, a radial distance R0 from the domed partition 38 is increased to an effective radius RE. An increase in the radial distance R₀ to the effective radius R_AND, by circumferentially spaced adjacent portions 74, increases the effective perimeter of the domed partition 38 to the perimeter P_AND!, as shown in Figure 12.

By inspection of Figures 10 and 11, it can be seen that by placing the dome pressing force further outward, as shown by the diameter DE2 and the radius RE, the moment arm of the bending force is reduced. That is, the possibility that a given force will unfold the inner convex annular portion 22 depends on the distance, radially inward, where the dome pressing force is applied. Therefore, increasing the inner diameter D0 to the effective diameter DE2 of the container body 64, and increasing the radial distance R0 to the effective radius RE, decreases the bending forces and thus increases the resistance to bending.

Also, as shown in Table 1, the radius R₉ is reduced; and, from the preceding description, it can be seen that this reduction in radius also helps container bodies 62 and 64 resist unfolding.

With continued reference to Figure 11, the first part 84 of the container body 64 is circumferential and could be considered to have a height H₄, and the adjacent part 86 is also circumferential and could be considered to have a height H₅. That is, defining the heights H₄ and H₅ it's a bit arbitrary. However, as can be seen, the adjacent portion 86 is disposed radially outward from the first portion 84; and the arcuate portion 76 of the dome arrangement portion 82 is formed with the radius R_H.

Thus, in effect, after reshaping a container body 64, the dome arrangement portion 82 is bowed out at distance Y from the abutment surface 18. This outward bow of the arrangement portion 82 is believed to Vault provides a part of the extraordinary increase in Vault Reversing Static Pressure. That is, when the domed concave septum 38 applies a downward force caused by pressure, the outwardly arched dome arrangement portion 82 tends to buckle elastically outward and / or both elastically and plastically. As the dome arrangement portion 82 tends to sag outwardly, it applies a winding force to the inner convex annular portion 22, thereby increasing the resistance to bending.

That is, while the downward force of the arched concave partition 38 presses downward tending to unfold both the outer convex annular portion 20 and the inner convex annular portion 22, the elastic and / or elastic and plastic camber of the arrangement portion 82 vault, tends to roll up the convex annular parts 20 and 22.

Similarly, as shown in Fig. 10, in circumferential portions of the container body 62 including the adjacent portions 74 and the arcuate portions 76, the tendency of the dome arrangement portion 70 to warp outward is similar to described for the dome arrangement portion 82. However, since the arcuate portion 76 exists only in the circumferential portions of the dome arrangement portion 70 where the adjacent portions 74 are located, the winding effect is not as great as in the container body 64.

Referring now to Figures 14-16, a concavity reformer apparatus 110 is disposed about a machine axis 111, and is provided to reshape the lower concave portion 25 of a container body 11. In Figures 14 and 15, a second stage taper mold 112 is disposed coaxial with the axis 111 of the machine and is included with the concavity reformer apparatus 110 so that an open end 114 of the container body 11 can be reformed. while reforming the lower concave portion 25. As shown in Figures 14 and 15, the container body 11 is positioned with the container axis 14 coaxial with the machine axis 111.

Referring now to Figures 14-17, the concavity reformer apparatus 110 and the taper mold 112 can be used in conjunction with a prior art taper machine 116 shown in Figure 17. The taper machine 116 includes a first narrowing stage 118 and a second narrowing stage 120. A feed chute 122 supplies container bodies 11 to a first star wheel

IS 2 129 396 T5

124 in the first taper stage 118. The first star wheel 124 rotates counterclockwise about an axis 126 of the first star wheel, as shown by arrow 128.

Consecutive container bodies 11 are collected from the feed chute 122 by successive rotary feed cavities 130 of the first star wheel 124. The first narrowing stage 118 includes twelve first shaping stations 132, as shown, whose positions generally correspond to each of the rotating feed cavities 130. The container bodies 11 remain at respective first forming stations 132, and rotate with their respective first forming stations 132, until they are deposited on a transfer chute 134.

The transfer chute 134 supplies consecutive container bodies 11 to a second star wheel 136 in the second narrowing stage 120. The second star wheel 136 rotates counterclockwise about an axis 138 of the second star wheel, as shown by arrow 140. Consecutive container bodies 11 are picked up from transfer chute 134 by successive second rotary cavities 142 of second star wheel 136. The second narrowing stage 120 includes twelve second forming stations 144, as shown, whose positions generally correspond to each of the second rotary cavities 142. The container bodies 11 remain in respective second forming stations 144 until they are deposited in an unloading chute 146.

The first and second sprockets 124 and 136 are connected to a support member 147 by means that are not shown and are not part of the present invention.

The prior art narrowing machine 116 performs a first drawing operation at the open end 114 of respective container bodies 11 while the container bodies 11 are arranged in respective first forming stations 132 of the first narrowing stage 118, reducing hence a diameter 148 of the open end 114 of each container body 11.

Then, when the container bodies 11 are supplied to the respective second forming stations 144 in the second narrowing stage 120, the narrowing machine 116 performs a second drawing operation on the open ends 114 of respective container bodies 11 as the Container bodies 11 are arranged at respective second shaping stations 144, thereby further reducing the diameter 148 of the open end 114 of each container body 11.

The narrowing molds 112 of Figures 14 and 15 are typical of those used with the narrowing machine 116 of Figure 17, one of the narrowing molds 112 being made for the first dimensions, and being used in each of the second positions. of conformation 144; and similar molds, not shown, being made for somewhat different dimensions, and being used at each of the first forming stations 132.

Preferably, the concavity reformer apparatus 110 is used in conjunction with the narrowing machine 116 of Figure 17, with a concavity reformer apparatus 110 being disposed at each of the second forming stations 144. Thus, at second shaping stations 144, a container body 11 is reformed into a container body 64 that includes an arcuate portion 76, as shown in Figure 11; and the open end 114 of the container body 64 is reshaped by a narrowing mold 112 while the container body 64 is disposed in the same second shaping station 144.

Referring again to Figures 14-16, and more particularly to Figure 16 in which the majority of the part numbers are placed, the concavity reformer apparatus 110 includes a stationary housing 150 having a canister seat 152. which is arranged longitudinally with respect to the geometric axis 111 of the machine, a pair of ball bearings 154 which are arranged in a hole 156 of the stationary housing 150, a rotating body 158 that is supported by ball bearings 154, and a driving gear 160 that is in one piece with rotating body 158.

As shown in Figures 16 and 16A, a pair of guide bars 162 are securely attached to rotating body 158. A pair of slide blocks 164 are slidably mounted on guide bars 162 so that slide blocks 164 can be slidable. move transversely with reciprocating movement with respect to the axis 111 of the machine. A drive shaft, or machining portion 166, is disposed in a hole 168 of the rotating body 158 and is longitudinally movable along the axis 111 of the machine. Longitudinal movement of drive shaft 166 is converted to transverse movement of slide blocks 164 by a pair of drive tie rods 170 that are rotatably attached to both drive shaft 166 and slide blocks 164. A pair of machining elements, or reformer rollers 172, are mounted on respective slide blocks 164 by mechanical roller axes 174.

The rotary body 158 is rotated by the tractor gear 160, and a reformer cam 176 is moved transversely with respect to the axis 111 of the machine by a mechanism, not shown, which is part of the narrowing machine 116 of Figure 17, thus that the drive shaft 166 moves longitudinally along the axis 111 of the machine, so that the reformer rollers 172 move transversely out of each other as the drive tie rods 170 convert the longitudinal motion of the drive shaft 166 to a transverse motion of the slide blocks 164.

IS 2 129 396 T5

Therefore, the container body 11 of Figures 3 and 4 reshapes to the container body 64 of Figures 7, 8 and 11 when the reformer cam 176 moves the drive shaft 166 longitudinally, the drive shaft 166 moves the drive struts 170, drive struts 170 move slide blocks 164, and slide blocks 164 move reformer rollers 172 into deforming contact with inner wall 42 of container body 11. That is, the drive shaft 166 is a part of the reformer apparatus 110, and the longitudinal movement of this one part results in a transverse movement of the machining elements, or reformer rollers 172.

Finally, the concavity reformer apparatus 110 of Figures 16 and 16A includes a machining device 178. The machining device 178 includes the rotary body 158, drive shaft 166, drive tie rods 170, guide bars 162, slide blocks 164 and machining elements 172.

Referring now to Figures 18-20, a concave reformer apparatus 180 is disposed about the axis 111 of the machine, and is provided to reshape the lower concave portion 25 of a container body 11. In Figures 18 and 19, a rotary stuffing apparatus 182 is disposed coaxial with the axis 111 of the machine and is included with the concavity reformer apparatus 180 so that an open end 114 of the container body 11 can be reformed while reforming. the lower concave portion 25. As shown in Figures 18 and 19, the container body 11 is located with the container axis 14 coaxial with the machine axis 111.

As shown in Figures 18 and 19, the rotary former apparatus 182 includes a mandrel 184, a control sleeve 186, and a narrowing disc 188 that work together to reshape the open end 114 of the container body 11 by a rotary operation, thereby narrowing container body 11 and rotatably flanging open end 114, which operations are a part of prior art technology.

Referring now to Figures 18, 19, and 21, the concavity reformer apparatus 180 and the rotary former apparatus 182 of Figures 18 and 19 may be used in conjunction with a prior art rotary former machine 190 shown in FIG. Figure 21.

Referring now to Figure 21, rotary forming machine 190 includes a feed chute 192 in which container bodies 11 progress inward and downward, with container axes 14 arranged horizontally. The feed chute 192 supplies the container bodies 11 to a can stop wheel 194. The boat stop wheel 194 rotates clockwise about an axis 196, as shown by arrow 198. As the can stop wheel 194 rotates, a container body 11 is picked up from the feed chute 192 by successive rotary feed cavities 200 in the can stop wheel 194.

Successive container bodies 11 are rotated around canister stop wheel 194 to a narrowing drum 202 that rotates counterclockwise about an axis 204, as shown by arrow 206. The bodies 11 of Containers are supplied to successive rotary cavities 208 of the narrowing drum 202 by the can stop wheel 194. The narrowing drum 202 includes sixteen shaping stations 210, the positions of which generally correspond to each of the cavities 208 of the narrowing drum. The container bodies 11 remain in the respective shaping stations 210 when the narrowing drum 202 rotates.

In the rotary forming machine 190, the open ends 14 of the container bodies 11, shown in Figure 18, are tapered and flanged by a rotary operation that is well known to container manufacturers. Subsequently, successive container bodies 11 are extracted from respective shaping stations 210 by respective discharge cavities 212 of a discharge wheel 214 that rotates clockwise about an axis 216, as indicated by arrow 218 .

Canister stop wheel 194, narrowing drum 202, and discharge wheel 214 are attached to frame member 219 by means not shown and not part of the present invention.

As the rotary forming machine 190, the rotary forming apparatus 182 and the method are part of the prior art, and are well known to container manufacturers, a simple description as given above is sufficient to show how the present invention is used in combination with this prior technique.

Referring now to Figure 20, the concavity reformer apparatus 180 includes a housing 220 having a one-piece gear 222, having a container receiving receptacle 224, and having a housing recess 226. Gear 222, socket 224, and housing hole 226 are all concentric with axis 111 of the machine. A pair of ball bearings 228 are snapped into housing bore 226; and a reformer body 230 is supported by ball bearings 228. The reformer body 230 includes a body hole 232 and a slot 234 that opens into the body hole 232.

A body extension 236 is attached to the reformer body 230 by any appropriate means, with particular attachment means not being part of the present invention. The body extension 236 includes a shaft opening 238, and an extension recess 240 that is open to both the shaft opening 238 and the slot 234. The shaft opening 238 is concentric with the shaft 111 of the machine.

IS 2 129 396 T5

The concavity reformer apparatus 180 also includes a guide bar 242 that traverses the body gap 232, and is attached to the reformer body 230 on opposite sides of the body gap 232, in the same manner as shown for guide bars. 162 of Figure 16A. A slide block 244 is slidably mounted on guide bar 242, and a machining element, or reformer roll 246, is mounted on slide block 244 by a mechanical roll axis 248 with a roll axis 250 parallel to axis 111 of the machine.

A drive shaft 252 is slidably inserted into the shaft opening 238 of the body extension 236. A drive clamp, or machining portion 254, is screwed onto drive shaft 252 and includes a clamp slot 256. A toggle bracket 258 includes a first leg 260 that is inserted into the clamp slot 256 and is rotatably attached to the drive clamp 254 by a pin 262 that rotatably secures the drive clamp 254 in the clamp slot 256 of the herself. Lever bracket 258 includes a second leg 264 that is rotatably attached to slide block 244 by pin 266. Lever bracket 258 is rotatably attached to reformer body 230 within slot 234 by pin 268, such that first and second legs 260 and 264 rotate around pin 268.

In operation, drive shaft 252 moves axially inward toward container body 11 by means of a cam not shown. Axially inward movement of drive shaft 252 is effective to move drive clamp 254 axially inward, thereby rotating toggle bracket 258 clockwise about pin 268. Clockwise movement of toggle bracket 258 moves pin 266 and slide block 244 radially, or transversely, away from machine axis 111, thereby moving reformer roll 246 radially outward to a deforming contact with the lower concave portion 25 of the container body 11.

Finally, the concavity reformer apparatus 180 of Figure 20 includes a machining device 269. The machining device 269 includes the reformer body 230, the drive shaft 252, the drive clamp 254, the toggle bracket 258, the rod guide 242, slide block 244 and machining element 246.

Referring now to Figure 22, a concavity reformer apparatus 270 includes a flanged housing 272 that may be attached to a non-shown can-making machine, which is not part of the present invention, by cap screws 274; and an extension housing 276 that is attached to flanged housing 272 by cap screws 278. Flanged housing 272 includes a housing hole 280 that is concentric with machine axis 111, and extension housing 276 includes an auxiliary hole 282 that is concentric with machine axis 111. A receptacle plate 284 includes a container receiving receptacle 285, is threaded into auxiliary recess 282, and is locked in a desired longitudinal position by a threaded retaining ring 286.

A reformer body 288 includes a threaded hole 290, a slot 292 that opens to threaded hole 290, and a large hole 294 that opens to slot 292. Threaded hole 290 is threaded into a tubular shaft, or machining part. 296, which is part of the aforementioned can making machine.

A guide bar 298 extends transversely through the large hole 294, and is fixedly inserted into the reformer body 288 on opposite sides of the large hole 294. A pair of slide blocks 300 are slidably mounted on the guide bar 298; and a pair of machining elements, or reformer rollers 302, are attached to respective slide blocks 300 by respective mechanical roller axes 304.

The can making machine, not shown, includes a drive shaft 308 with a threaded portion 310, and is inserted through the tubular shaft 296. A drive clamp or machining portion 312, of the concavity reformer apparatus 270, is threaded on threaded portion 310; and the drive clamp 312 includes a clamp slot 316.

A pair of toggle brackets 318 are rotatably attached to reformer body 288 in slot 316, by respective pins 320. Toggle brackets 318 include first legs 322 that are disposed in slot 316 of the bracket and that are rotatably attached to the bracket. drive clamp 312 by respective pins 324. Also, toggle brackets 318 include second legs 326 that are rotatably attached to respective slide blocks 300 by respective pins 328.

In operation, the can making machine, not shown, provides a rotary motion to the tubular shaft 296, thereby rotating the reformer body 288 along with the slide blocks 300 and the reformer rollers 302 so that the reformer rollers 302 move. on a rotary path that is arranged radially outward from the axis 111 of the machine, which is also the axis 14 of the container body 11.

The can-making machine provides cam-actuated movement of drive shaft 308, longitudinally inward, toward container body 11. This longitudinally inward movement of the drive shaft 308 moves the drive clamp 312 longitudinally inward, moves the first branches 322 of the lever brackets 318 longitudinally inward, rotates the lever brackets 318 around the respective pins 320, separates the sliding blocks 300 transversely outwards from each other,

ES 2 129 396 T5 or radially outward, and moves the reformer rollers 302 into deformation contact with the container body 11 on opposite sides of the lower concave portion 25.

Finally, the concavity reformer apparatus 270 of Figures 22 and 22A includes a machining device 329. The machining device 329 includes the tubular shaft 296, the reformer body 288, the drive shaft 308, the drive clamp 312, the Lever Brackets 318, Guide Bar 298, Slide Blocks 300, and Machining Elements 302.

Referring now to Figure 23, a concavity reformer apparatus 330 includes a receptacle plate, or body 332, that is attached to a frame member 334 by bearings 336 coaxial with machine axis 111, and plate 332 The receptacle includes a container receptacle 338 that is coaxial with the axis 111 of the machine.

The concavity reformer apparatus 330 also includes a transverse slide 340 that is attached to the frame member 334 by any suitable means for transverse movement relative to the machine axis 111, the method of attachment not forming part of the present invention. Ball bearings 342 are mounted on transverse slide 340, and a reformer shaft, or machining part 344, is rotatably mounted on ball bearings 342.

Referring now to Figures 23 and 24, four machining elements 346 are inserted into receptacles 347 of reformer shaft 344 and are attached to reformer shaft 344 by respective cap screws 348. Thus, machining elements 346 cooperate with reformer shaft 344 to provide a reformer roll 350 having a plurality of outwardly and radially extending protrusions 352, and are circumferentially spaced, which are a part of machining elements 346. .

As shown in the drawings, when the transverse slider 340 moves transversely, the protrusions 352 of the reformer roll 350 move radially outward into a deforming contact with the lower concave portion 25 of the container body 11. If the receptacle plate 232 and container body 11 can rotate freely, and if the reformer roll 350 has an effective diameter 354 that is in a predetermined relationship with diameter D₀ of the lower concave portion 25 of the container body 11, respective machining elements 346 will cooperate with other machining elements 346 to progressively form a plurality of negatively sloping portions, or circumferentially spaced arcuate-shaped portions 100, of the lower concave portion 25, which deform radially outward, as shown in Figures 5 and 6.

Furthermore, if the receptacle plate 332 and container body 11 are rotated at a predetermined speed ratio with the reformer roll 350 by any appropriate mechanism, which is not part of the present invention, tracking of the elements of the present invention is ensured. machining 346 with the parts 100 circumferentially spaced.

Finally, the concavity reformer apparatus 330 of Figures 23 and 24 includes a machining device 358. The machining device 358 includes the body transverse slide 340, the ball bearings 342, the reformer shaft 344, and the bearing elements. machining 346, which combine to form reformer roll 350.

Referring now to Figure 25, a concavity reformer apparatus 360 is shown in which a half section 361 thereof is disposed below a section line 362, and a half section 363 is disposed above section line 362. The middle Section 361 presents reformer apparatus 360 in its inactive state, and half section 363 presents reformer apparatus 360 activated in its drawn state.

Referring now to Figure 25A, internal parts of the half section 361 of Figure 25 have been reproduced in this Figure 25A to allow clear numbering of the various parts thereof.

Referring now to Figures 25 and 25A, the concavity reformer apparatus 360 includes a forward receptacle 364 and a container receptacle 365. The container receptacle 365 includes a container receptacle 367 and is separated from the front receptacle 364 by a threaded fitting ring 366 that is threaded into the front receptacle 364, and the container receptacle 365 is attached to the front receptacle 364 by cap screws. 368.

A flanged guide sleeve 370 is attached to the front socket 364 by cap screws 372, extends longitudinally in a hole 374 of the container socket 365, and includes a bearing hole 376. A tubular bearing 378 is pressed into bearing bore 376.

The forward socket 364 is attached to a can making machine, not shown, by a threaded end 380 of a tubular shaft, or machining portion 382, ​​of the can making machine. A drive shaft 384 of the can making machine is slidably inserted through tubular shaft 382 and includes a threaded portion 386.

A forming head 388 is threaded onto threaded portion 386 and includes a plurality of inclined planes 390. A plurality of machining elements, or drawing elements 392, are circumferentially spaced,

ES 2 129 396 T5 are located close to respective inclined planes 390, and respective slide bearings 394 are arranged between respective inclined planes 390 and the drawing elements 392.

Longitudinal movement of the drawing elements 392 is impeded by the engagement of tabs 396 of the drawing elements 392 which engage in an inner groove 398 of the flanged guide sleeve 370, and by a flange 400 of the flanged guide sleeve 370, which extends inwardly, engaging respective outer grooves 402 of embossing elements 392.

In operation, as shown by the half section 363, the longitudinally inward movement of the drive shaft 384 moves the drawing elements 392 radially outward in response to contact of the inclined planes 390 through the slide bearings 394, drawing by this, radially outward, a plurality of circumferentially spaced portions 100 of the lower concave portion 25 of the container body 11, to form the container body 62 shown in Figures 5 and 6.

Then, when the drive shaft 384 moves longitudinally away from the reshaped container body 62, a plurality of springs 404 move respective drawing elements 392 radially inward, so that the reshaped container body 62 can be removed from the reformer apparatus 360. concave, and so that the lower concave portion 25 of another container body 11 can be positioned around the embossing elements 392.

Referring now to Figures 14-25, in the concavity reformer apparatus 110 of Figures 14-16, the reformer rollers 172 rotate in a path that is disposed radially outward from the container axis 14, and the reformer rollers 172 are they move radially outward into deforming contact with the lower concave portion 25 of the container body 11, while the container body 11 remains rotatably stationary.

Since the container body 11 remains rotatably stationary, the concavity reformer apparatus 360 of Figure 25 could be replaced by the concavity reformer apparatus 110 of Figures 14-16. In addition, either the concavity reformer apparatus 110 of Figures 14-16, or the concavity reformer apparatus 360 of Figure 25, could be used in conjunction with either one or both of the shaping stations 132 or 144 of the tapering machine 116 of Figure 17.

Furthermore, even though the concavity reformer apparatus 110 of Figures 14-16 has been shown in conjunction with a non-rotatable container body 11, the reformer apparatus 110 of Figures 14-16 is equally suitable for use with a machine, such as the rotary forming machine 190 of Figure 21, in which the container body 11 rotates.

Referring again to Figures 18-20, although a single reformer roll 246 has been shown and described in conjunction with a single lever bracket 258 and a single slide block 244, the mechanism described in conjunction with Figure 22, in the two reformer rolls 302 are used, it could replace the mechanism described in Figures 18-20.

Furthermore, although a single guide bar 242 or 298 has been shown in the embodiments of Figures 20 and 22, this has been done for the purpose of avoiding undue complexity in the drawings and descriptions. It should be understood that, in the embodiments of Figures 20 and 22, two guide bars could be used such as guide bars 162 of Figures 16 and 16A. However, if the guide bars 242 and 298 of Figures 20 and 22, respectively, are assumed to be rectangular in cross-section, this cross-sectional shape would prevent the sliding blocks 244 and 300 from rotating around the respective link bars. guide 242 or 298, and the use of two guide bars 242 or 298 is unnecessary.

Finally, the concavity reformer apparatus 360 of Figures 25 and 25A includes a machining device 406. The machining device 406 includes the forward socket 364 that cooperates with the flanged guide sleeve 370 to serve as a body 408, the tubular shaft 382 , drive shaft 384, stuffing head 388, and machining elements 392.

Referring now to Figures 26-28, a concavity reformer machine 410 of Figures 26-28 includes a plurality of concavity reformer apparatuses 412 of Figures 26 and 27.

Referring now to Figures 21 and 28, the concavity former machine 410 is constructed, as regards the handling and transportation of the container body 11, along the lines of the rotary former machine 190 of Figure 21: depositing respective container bodies 11 in cavities 208 of forming station narrowing drum 210, and transporting container bodies 11 around drum 202 during the reforming process.

Therefore, the numbers and terminology used to describe the concavity former machine 410 are, for most parts, the same as those used to describe the rotary former machine 190. However, the concavity reforming machine 410 is designed to perform only the concavity reforming operation, although, as previously thought, the concavity reforming operation can be carried out substantially simultaneously with several other can forming operations.

IS 2 129 396 T5

The concavity reformer machine 410 receives container bodies 11 on the feed chute 192, transfers the container bodies 11 to successive cavities 208 of the shaping stations 210 of the drum 202 by means of the can stop wheel 194, transports the container bodies 11 around drum 202 to respective discharge cavities 212 of discharge wheel 214, and deposits container bodies 11 on discharge chute 414.

A revolving drum 416 of Figure 26, omitted from Figure 27 but shown in Figure 28, is disposed concentric with axis 204 of drum 202 and rotates with drum 202 in the direction of arrow 206.

A plurality of concavity reformer apparatuses 412 are attached to the revolver drum 416 of the concavity reformer machine 410 of Figure 28, one at each of the forming stations 210, but with a few removed to more clearly see other details of the 410 concavity reformer machine.

Referring now to Figures 26 and 27, the concavity reformer apparatus 412 comprises a dome receptacle device 418 that includes a flanged mounting plate 420 with a flange 422, a bearing hole 424 that is disposed concentric with shaft 14 of the container, a threaded hole 426, and mounting holes 428 that are disposed in the flange 422. Flanged mounting plate 420 is attached to revolving drum 416 by cap screws 430 inserted into mounting holes 428.

The dome receptacle device 418 further includes a pair of ball bearings 432 that are disposed in the bearing hole 424, a threaded retaining ring 434 that is disposed in the threaded hole 426 and that retain the ball bearings 432 therein. bearing hole 424, and a concave socket 436 with a pair of bearing receiving surfaces 438 receiving respective ball bearings 432. The dome receptacle 436 also includes a container receiving receptacle 440.

The concavity reformer apparatus 412 also includes a guide shaft, or machining portion 442, which is cylindrical in shape, and which is disposed in a guide hole 444 of the revolver drum 416, the guide hole 444 being parallel to the axis 14 of the container. Since the guide hole 444 is disposed in the revolver drum 416, the revolver drum 416 is a part of each of the concavity reformer apparatuses 412 that are disposed around the revolver drum 416.

A machining element, or reformer roll 446, is attached to the guide shaft 442 by a mechanical roll shaft 448, the reformer roll 446 and the roll shaft 448 being disposed about a roll axis 450 that is eccentric with the shaft. 14 of the container.

Finally, the concavity reformer apparatus 412 includes a guide arm 452 that is attached to the guide shaft 442 by any appropriate means, which is not part of the invention; a cam follower shaft 454 that is inserted into a hole 456 in guide arm 452; and a cam follower 458 that is rotatably attached to the cam follower shaft 454. As shown in Figure 26, the guide arm 452 is attached to the guide arm 442 near an end 460 that is opposite an end 462 at which the dome receptacle device 418 is disposed.

The concavity reformer apparatus 412 of Figures 26 and 27 includes a machining device 463. The machining device 463 includes the revolving drum 416 serving as the body, the guide shaft 442, the guide arm 452, the cam follower 458, roller shaft 448 and machining element 446.

The concavity reformer machine 410 of Figure 28 includes a cam 464 that is disposed about the axis 204 of the drum 202, but is stationary with respect to the drum 202. That is, the concavity reformer apparatus 412 is attached to the drum 202 and rotates around cam 464 in the direction of arrow 206.

In operation, as drum 202 rotates about axis 204, successive concavity reformer apparatus 412 move about axis 204, and successive cam followers 458 contact an elevation 470 of cam 464, thereby rotatably locating the guide axis. , or machining portion 442, of that particular concavity reformer apparatus 412; thereby rotating the reformer roll 446 outwardly into deformation contact with the lower concave portion 25 of the container body 11.

In summary, the present invention provides for relative transverse motion between a machining member 172, 246, 302, 346, 392, or 446, and a container body 11. The machining element 172, 246, 302, 346, 392, or 446, or the container body 11, or both, can rotate about the container axis 14, or they can both remain rotatably stationary. If more than one machining element 172, 246, 302, 346, 392, or 446 is arranged, they are radially and circumferentially spaced, and the machining elements may be rollers 172, 246, 302, 350, or 446, or embossing 392. Preferably, machining elements 172, 246, 302, 346, 392, or 446 move radially or transversely outwardly in response to movement of another part of the tool, such as a drive shaft 166, 252, 308, or 384; and preferably, this movement of the other part of the tool is rotary or longitudinal.

Furthermore, the reform of the lower concave portion 25 of the container bodies 11, which is obtained with the apparatus and method of the present invention, produces container bodies 64 with arcuate portions 76 that extend circumferentially around the lower concave portion. 80, as shown in Figures 7 and 8; or container bodies 62 with

ES 2 129 396 T5 a plurality of circumferentially spaced arcuate shaped portions 100, as shown in Figures 5 and

6.

In summary, as shown and described herein, the apparatus and method of the present invention provides container bodies 62 and 64 in which improvements are achieved in unfolding strength, dome reversal static pressure, and height. cumulative drop, without increasing the thickness of the metal, without decreasing the radius R₄ of the vault, without increasing the positional distance L₂, without increasing the height Hj of the dome, and without appreciably decreasing the fluid capacity of the container bodies 62 and 64. Or otherwise, the present invention provides container bodies 62 and 64 in which satisfactory values ​​of unfold strength, dome reversal static pressure, and cumulative drop height can be achieved using a metal of thicker thickness. thinner than has been possible so far.

The present invention is believed to produce unexpected results. Whereas, in prior art designs, a decrease in the dome radius R4 has decreased the dome inversion pressure, in the present invention, a decrease in the dome radius R4, combined with a reinforcement of the portion 70 u 82 dome arrangement, achieves a remarkable increase in both dome reversal pressure and cumulative drop height resistance.

Furthermore, the fact that the extraordinary increase in cumulative drop height strength and dome reversal static pressure have been achieved by simply reshaping a container body of standard dimensions is believed to be unexpected results.

When referring to the dome radii R4, or the limits thereof, it should be understood that, while the arched concave partitions 38 of the container bodies 62 and 64 have been made with tools having a spherical radius, both the elastic recovery of the domed concave partition 38 of the container body 11, as the reform of the container body 11 to container bodies 62 and 64, changes the radius of the dome from a true spherical radius.

Therefore, in the claims, a specified radius, or radius range for radius R4, will apply to either a central portion 92 or an annular portion 94, both of Figures 5 and 7.

The central part 92 has a diameter D_CP which can be any percentage of the diameter D_P of the domed concave partition 38; and the annular portion 94 may be disposed at any distance from the axis 14 of the container and may have a radial width X₄ of any percentage of diameter D_P of the domed concave septum 38.

Furthermore, although the preceding description is focused on central partitions 38 with radii R4 that are generally spherical, and that are made with spherical machining, the present invention is applicable to container bodies 62 or 64 in which the domed concave partition 38 is ellipsoidal. , consisting of annular steps, decrease its radius of curvature as a function of the radially outward distance of the domed concave partition 38 from the axis 14 of the container, has any part 92 or 94 that is substantially spherical, includes a part that is substantially conical, and / or includes a part that is substantially flat.

Finally, although the pertinent limits to the shape of the central partition 38 can be defined as functions of the radii R₄ vault, the limits relevant to the shape of the central partition 38 may be defined as limits for the central part 92 or for the annular part 94 of the central partition 38, or as limits for the angle α₃, either on the perimeter P₀ or to any other radial distance from the axis 14 of the container.

Referring finally to Figures 4-11, another distinctive difference of the present invention is in the slope of the inner walls 71 and 83 of container bodies 62 and 64, respectively. As seen in Figure 4, the prior art inner wall 42 is inclined upward and inward by an angle α₁.

In stark contrast to the prior art, the inner wall 83 of the container body 64 of Figures 7, 8, and 11 includes a negatively sloped portion 96 that is inclined upward and outward at a negative angle α₅. As seen in Figure 8, the negative slope portion 96 extends circumferentially about the axis 14 of the container.

Also in stark contrast to the prior art, the inner wall 71 of the container body 62 of Figures 5, 6 and 10 includes a negatively sloping portion 98 that is inclined upward and outward at a negative angle α₆, and which is arcuately disposed about less than half of the bottom 66 of the container body 62. The inner wall 71 also includes another negatively sloping portion 100 that is inclined upward and outward by a negative angle α₆, and which is circumferentially spaced from the negative slope portion 98.

Therefore, in the appended claims, it is to be considered that the central partition 38 is not limited to a particular or unique geometric shape.

In summary, the present invention provides these remarkable and unexpected improvements by means of an apparatus and method such as those mentioned in the aspects of the invention included herein.

Although aluminum container bodies have been investigated, it is believed that the same principles, namely to increase

ES 2 129 396 T5 the resistance to unfolding of the inner wall, from the inner wall 42 of the container body 11 to either the inner wall 71 of the container body 62, or to the inner wall 83 of the container body 64, it would be effective in increasing the strength of container bodies made of other materials, including ferrous and non-ferrous metals, plastics, and other non-metallic materials.

Referring finally to Figures 1 and 2, the upper packages 10 are stacked on the lower packages 10 with the outer connecting portions 28 of the upper packages 10 nested within the double-flanged upper portions 56 of the lower packages 10; and both containers 10, arranged adjacently and stacked vertically, are packaged in a package 58 using a shrink wrap 60.

Although this packing method is more economical than the previous box packing method, possible warping due to rough handling becomes a problem, so that the requirements for the cumulative drop strengths of the containers 10 are more rigorous. It is this problem that the present invention addresses and solves.

Although specific methods and apparatus have been set forth in the foregoing description, it should be understood that these specifications have been given for the purpose of setting forth the principles of the present invention, and that many variations thereof would be apparent to those skilled in the art. Therefore, the scope of the present invention should be determined by the appended claims.

Industrial applicability

The present invention is applicable to container bodies made of aluminum and various other materials. More particularly, the present invention is applicable to beverage containers of the type having a seamless, drawn and drawn cylindrical shaped body, and a bottom of the same piece with an annular bearing part.