MXPA03012003A

MXPA03012003A - Can shell and double-seamed can end.

Info

Publication number: MXPA03012003A
Application number: MXPA03012003A
Authority: MX
Inventors: R Stodd Peter
Original assignee: Container Dev Ltd
Priority date: 2001-07-03
Filing date: 2002-07-01
Publication date: 2005-07-01
Also published as: EP1434894A2; JP2004533933A; US20030121924A1; CN1321862C; IL159505A0; EP1434894B1; RU2003137570A; WO2003004716A3; AU2002354810B2; BR0211033B1; JP4647207B2; RU2323796C2; CA2451453A1; BR0211033A; CA2451453C; CN1524049A; EP1434894A4; WO2003004716A2; NZ530353A

Abstract

A drawn aluminum can shell has a peripheral crown which is double-seamed with an end portion of an aluminum can body to provide a can end having a generally flat center panel connected by a curved panel wall to an inner wall of an annular U-shaped countersink. The countersink has a generally cylindrical outer wall and an inner width less than the radius of the panel wall. The outer wall of the countersink connects with a lower wall portion of a frustoconical chuckwall at a junction below the center panel, and an upper wall portion of the chuckwall extends to an inner wall of the crown at an angle of at least 16¦ with the center axis. In one embodiment, the chuckwall has an intermediate generally vertical short riser portion connecting the wall portions, and the inner bottom width of the countersink is less than .040 inch.

Description

CAN AND EXTREME CAN WITH DOUBLE COS URA Environment of the invention. This invention relates to the construction or forming of a metal or aluminum foil tin shell and to an end of the can having a peripheral edge or crown that is double stitched to the upper edge portion of a can body of sheet metal or aluminum. That end of the can is formed of a stretched metal sheet can shell, for example, a shell produced by machining, as described in US Patent No. 5,857,374, issued to the applicant. Commonly, the shaped can shell includes a circular central panel extending toward a wall of the panel extending towards, or also forming, the inner wall of a reinforcing or flared rib having a U-shaped cross section configuration. The flare is connected by a truncated mandrel with an annular crown that is formed with a peripheral curl. For beverage containers, the center panel of the shell is commonly provided with an EZ flange to open and after the body is filled with a drink, the shell crown curled peripherally is stitched double to the end portion upper body of the can.

When the body of the can is filled with a carbonated drink, or with a drink that must be pasteurized to; At high temperature, it is essential that the end of the can have a substantial resistance in the clamp to withstand the pressurized beverage, for example, a clamp resistance of at least 90 psi. That resistance to "clamp" pressure and "rock" pressure is described in detail in US Patent No. 4, 448, 322, the disclosure of which is incorporated by reference. It is also desirable to minimize the weight of the metal foil or aluminum within the end of the can, without reducing the strength of the clamp. This is achieved either by reducing the thickness or the gauge of the flat sheet of metal from which the can is stretched and formed and / or by reducing the diameter of the cut circular space of the metal sheet to form the shell of the can.

There have been many metal sheet shells and can ends constructed or proposed to increase the strength of the end clamp of the can and / or reduce the weight of the metal sheet within the end of the can, without reducing the strength of the can. the clamp For example, US Patents No. 3,843,014, No. 4,031,837, No. 4, 093, 102, the, above mentioned No. 4, 448,322, No, 4,790,705, No, 4,808,052, No, 5,046,637, No, 5,527,143, No. 5, 685,189, No ... 6, 065, 634, No. 6, 089, 072 and No. 6, 102, 243, describe various shapes and configurations of can shells and can ends, and the various dimensions and configurations that have been proposed or used to increase the strength of the end clamp of a can and / or reduce the metal at the end of the can. Also published PCT application No. O 98/34743, describes a modification of the shell of the can and the end of the can described in the aforementioned Patent No. 6,065,634. In addition to increasing the strength / weight ratio of the end clamp of a can, it is desirable to form the shell of the can so that there is a minimum of modifications required for the extensive machining that exists in the field to add the EZ tabs of opening to the shells of cans, and to double sew the shells of tin to the bodies of the cans. While some of the can shells and can ends described in the above patents provide some of the desirable structural representations, none. of patents provides all representations.

Description of the invention The present invention is directed to an improved sheet metal shell and can end, and to a method for forming the end of the can that provides the above-mentioned desirable representations and advantages., including a significant reduction in the diameter of the space to form a can shell and a significant increase in the strength / weight ratio of the end of the resulting can. A can shell and a can end formed according to the invention, not only increase the strength of the end clamp of the can, but also minimize the changes or modifications in the existing machining to add opening EZ tabs to the shells of the can, and to double sew the shells of the cans to the bodies of the cans.

According to a representation of the invention, the shell of the can and the end of the can are formed with a general height between the crown and the flaring of less than .240 of an inch, and preferably of less than .230 of an inch, and the flared generally has a cylindrical outer wall and an inner wall connected to a curved panel wall. A generally truncated mandrel wall extends from the outer wall of the flared towards the inner wall of the crown, and has an upper portion of the wall extending at an angle of at least 16 ° relative to the central axis of the shell, and preferably between 25 ° and 30 °. The flaring may have a generally flat bottom wall that connects to the outer wall of the flaring with a small radius, substantially less than the radial width of the bottom wall, and the interior width of the flaring at its bottom is less than the radius of the panel wall.

According to a modification of the invention, a can shell and a can end may have some of the structure above, and the gasket being a portion of the bottom wall of the flared and the flared outer, substantially below the center panel . The portion of the lower wall of the flared extends at an angle less than 16 ° relative to the central axis and is connected to the portion of the upper wall of the flared through a generally vertical rising short portion and accurate radii, forming a key of interlocking The flare has a radius of curvature substantially smaller than the radius of curvature of the wall of the curved panel, and the interior width of the flare at the bottom of the flare is also less than the radius of the panel wall, and preferably less than. 030 of an inch Other representations and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

Brief description of the drawings. Figure 1 is a vertical cross-section through a sheet metal can shell formed in accordance with the invention; Figure 2 is an enlarged fragmentary section of the can shell of Figure 1, and shows the configuration of a representation; Figure 3 is a smaller fragmentary section of the can shell of Figure 2, and shows the can shell becoming a can end with a double seam mandrel and a first stage roller; . Figure 4 is a fragmentary section similar to Figure 3 and shows a can end in double seam with 1 mandrel and a second stage roller; Figure 5 is an enlarged fragmentary section of the can end with double seam shown in Figure 4, and with a fragment of the modified double seam mandrel; Figure 6 is a section similar to Figure 1 and shows a can end with double seam formed in accordance with the invention; Figure 7 is an enlarged fragmentary section similar to Figure 2 and showing a can shell formed in accordance with a modification of the invention; Y Figure 8 is an enlarged fragmentary section similar to Figure 5 and showing the can shell of Figure 7 with double stitching in a can body.

Description of preferable representations. Figure 1 illustrates a one-piece shell (10), which is formed of a substantially circular sheet metal or aluminum space, which preferably has a thickness of about .0085 inch and a space diameter of about 2705. inches The shell (10) has a central axis (11) and includes a central panel (12) slightly crowned with an annular portion (14) extending towards a curved wall (16) of the panel. The central portion (14) of the panel wall and the wall (16) of the panel can be formed by a series of combined curved walls having radii in which Rl is 1,489 inches, R2 is .321 inch, R3 it is .031 of an inch, and 4 is .055 of an inch. The curved wall (16) of the panel has an internal diameter ID at the bottom of about 1,855 inches.

The curved wall (16) of the panel with the radius R4 extends from an inner wall (17) of a reinforcement rib (18) having a U-shaped cross section configuration and including a wall (22) ring plane at the bottom and a generally cylindrical outer wall (24) having an inner diameter D2, for example, of about 1,957 inches. The flat wall (22) of the bottom of the flaring (18) is connected to the wall (16) of the inner panel and to the outer wall (24) of the flaring through the curved corner walls (26), each with an inner radius R5 of about .010 of an inch. The radial width of the flat bottom wall (22) is preferably .022 inch, so that the width Wl of the inner bottom of the flared (18) is about .042 inch.

The outer wall (24) of the flaring (18) connects' with a generally tronconical mandrel wall (32), through a curved wall (34) having a radius R6 of about .054 of an inch. The mandrel wall (32) extends at an angle Al of at least 16 ° with respect to the central axis (11) or to a vertical reference line (36) which is parallel to the central axis (11) of the shell. Preferably, the angle Al is between 25 ° and 30 ° and of the order of 29 °. The upper end of the mandrel wall (32) connects to the bottom of an inner curved wall (38) of a round crown (42) having a curled outer wall (44). Preferably, the inner wall (38) of the crown (42) has a radius R7 of about .070 of an inch, the diameter D3 inside the bottom of the inner curved wall (38) is about 2039 inches, and the diameter D4 outer wall (44) outside curly is about .240 inches. The height C of the outer curled wall (44) is within the range of .075 of an inch and .095 of an inch, and is preferably of about .079 of an inch. The depth D from the bottom of the outer curled wall (44) or of the joint (46) of the mandrel wall (32) and of the wall (38) of the inner crown, to the inner surface of the wall (22) ) of the bottom of the flaring, is within the range of between .108 of an inch and .148 of an inch, and preferably of about .126 of an inch. The connection (47) or the center point for the radius R6 has a depth G of about .079 from the joint (46) or the bottom of the outer curved wall (44) of the crown (42).

: Figure 3 shows the crown (42) of the shell (10) which is double stitched in an upper portion (48) of the peripheral end of a metal sheet or aluminum can body (50). The double stitching operation is carried out between a rotating double-stitched circular mandrel (55) that engages the shell (10) and has an outer surface (58) that can be slightly narrowed between an angle of 0 ° and 20 ° with respect to the axis central of the mandrel (55) and the common central axis (11) of the shell (10). Preferably, the surface (58) has a slight narrowing of about 4 ° and is engaged through the inside wall (38) of the crown (42) in response to the radially inward movement of a double-seam roll (60). first stage, while the body (50) of the can and its contents and the shell (10) are rotating or rotating with the mandrel (55). The mandrel (55) also has a "tronconical" surface (62) engaging with and meshing the conical core wall (32) of the shell (10), and a portion (64) projecting an annular lip of the core (55). ) extends inside the flare (18), and has a bottom surface (66) (Figure 5) and an external cylindrical surface (68) that engages the wall (22) of the bottom and the exterior wall (24) of the flare ( 18), respectively.

Figures 4 and 5 illustrate the termination of the double stitching operation to form a double stitched crown (70) between the rotary mandrel (55) and a double seam roll (72) of the second stage, which also moves radially toward inside, while the mandrel (55), the shell (10) and the body (50) of the can are rotating to convert the shell (10) to one end (75) of the can, which is positively joined and sealed to the portion (48) of the upper end of the can. body (50) of the can. The edge or the crown (70) with double stitching have an inner wall (74) which is formed from the inner wall (38) of the crown (42) of the shell, and also have an outer wall (76) formed from of the crown (42) of the shell, including the outer curled wall (44). The crown (70) with double seam has a height H2 within the range of between .090 inch and .110 inch, and preferably about .100 inch. The end (75) of the can has a general height Hl between the top of the crown (70) and the bottom of the flare (18), within the range of .170 of an inch and .240 of an inch, and preferably of near of .235 of an inch. Since the end (75) of the can has the same cross-sectional configuration as the shell (10), with the exception of the crown (70) with double stitching, for the common structure the; same common reference numbers in Figures 4-6.

As - it is apparent from Figure 6, the central portion of the central panel (12) defines a plane (80) substantially intersecting the junction (46) of the mandrel wall (32) with the inner wall (74) of the crown (70) with double stitching. The opening tab E-Z has been omitted in Figure 6 for purposes of clarity and simplification, and since the opening tab E-Z is not part of the present invention.

Figures 7 and 8 show another representation or modification of the invention, including a can shell (Figure 7) and a double stitched can end (Figure 8). Accordingly, the structural components corresponding to the components described above in connection with Figures 1-6, have the same reference numbers but with the addition of premium marks. Thus, referring to Figure 7, a can shell (10 ') has a central axis, which is the same as the axis (11) and includes a central circular panel (12') connected to a peripheral wall (16 '). of the curved panel, which is connected to a wall (27 ') inclined inside of a flared (18') having a cross-sectional configuration in the form of ü. The flare has a generally cylindrical outer wall (24 ') extending at an angle of less than 10 ° and connecting with a mandrel wall having a portion (32') of a top truncated wall and a portion (34 ') of bottom wall slightly curved. The wall portions (32 ') and (34') are connected through a latching key or a generally vertical upward cutting portion (35) having relatively narrow inner and outer radii, for example, of the order of .020 of inch. The upper portion (32 ') of the mandrel wall is connected through a curved wall (37') to the inside curved wall (38 ') of a crown (42'), which has an outer wall (44 ') curved The inner wall (38 ') of the crown (42') connects to the upper portion (32 ') of the mandrel wall in a joint (46'), and the outer wall (24 ') of the flaring (18') connects to the lower portion (34 ') of the mandrel wall in a joint (47'). The vertical height Gl from the bottom of the flaring (18 ') to the latching key or the ascending portion (35') is close to .086. The radius R20 is about .051 inch, and the portion (34 ') of the bottom wall extends at an angle A3 of about 15 °. The flared (18 ') has a radius R9 of about; .009 to .011 of an inch. Other dimensions and approximate angles for the shell (10 ') shown in Figure 7 are as follows: Cl .082 in. Wl .024 in. H5 .078 in C2 .153"W2 .063 H6 .149" D6 1.910"W3 .034 D7 2.036" A2 .29 ° D8 2.337"A3 15 ° D9 1.731"? 4 16 °? 6 13 ° It has been found that the particular configuration of the cross section of the can shell (10 ') provides performance results superior to the performance results provided by the can shell (10). Accordingly, the details of the configuration of the can shell (10 ') include a portion (32') of the upper wall of the mandrel wall having an angle 2 2, relative to the central axis, of at least 16o- and preferably within the range of 25 ° to 30 °. The portion (34 ') of the lower wall of the mandrel wall forms an angle A3 that is close to 15 °. The interior wall (38 ') of the crown (42) forms an angle 4 4 preferably within the range of 5 ° to 30 °, and preferably of about 16 °. The inner wall (17 ') of the flaring' (18 ') forms an angle? 6 which is greater than 10 ° and close to 13 °. The width Wl at the bottom of the flaring between the inner wall (IV) and the outer wall (24 ') is less than .040 of an inch and preferably of about .024 of μ ^ 3? 3. The radius R8 of the curved wall (16 ') of the interior panel is substantially greater than the width Wl of the flare (18'), and is about .049 of an inch.

The crown (42 ') of the shell (10') has a height Cl within the range of .075 of an inch to .095 of an inch, and preferably of about .082 of an inch, and a height of C2 within the range of. 120 of an inch and .170 of an inch, and preferably of about .153 of an inch. The overall diameter D8 of the shell (10 ') is about 2,337 inches,; and the diameter D7 towards the junction (46 ') is about 2036 inches. The inner diameter D6 of the bottom of the outer wall (24 ') of the flared is about 1,910 inches, and the difference W2 between D7 and D6 is greater than the width Wl of the flared, or about .063 inch. The diameter D9 for the center of the radius R8 is about 1,731 inches. It is understood that if a shell of different diameter is desired, the diameters D6-D9 vary proportionally. The height H5 of the central panel (12 ') on the! bottom of the flared (18 ') is within the range of .070 of an inch and .110 of an inch, and preferably about .078 of an inch. The height H6 of the shell (10 ') between the upper part of the central panel (12') and the upper part of the crown (42 '), is within the range of .125 of an inch and .185 of an inch, and preferably about .149 of an inch.

Referring to Figure 8, the shell (10 ') is double stitched with the portion (48') of the upper end of a can body (50 ') formed using substantially the same machining as that described above in connection with Figures 3-5 to form a can end (75 '). This: is, a seaming mandrel (not shown), similar to the mandrel (55), includes a lower portion similar to the. portion (64) projecting within the flare (18 '), and having surfaces corresponding to the surfaces (58), (62) and (68) of the sewing mandrel (55) for; engaging the wall (24 ') of the outer flaring,' the portion (32 ') of the mandrel wall, and to form the interior wall (74') of the crown (70 ') stitched double. As also shown in Figure 8, the inner wall (74 ') of the double sewn crown (70') extends to a light angle A5 of about 4 o, and the overall height H3 of the end (75 ') of the can is less than .240 of an inch, and preferably of about .235 of an inch. The height H4 of the double sewn crown (70 ') is of the order of .100 of an inch, and the height H7 from the top of the crown (70') to the top of the central panel (12 ') is greater than the height H5 of the central panel, preferably about .148 of an inch.

By forming a shell and a can end with the configuration and dimension described above, it has been found that the end of the can will withstand a pressure inside the top can of 110 psi before the end of the can is rolled up. The configuration and relatively shallow profile of the end of the can result in a general height of less than .240 of an inch, and also provide a significant reduction of more than .040 of an inch in the diameter of the circular space used to form the shell. This reduction results in a significant reduction in the width of the aluminum sheet or net used to produce the shells, and therefore a reduction in the weight and cost of the aluminum to form the ends of the cans, which is especially important in view of the large volume of can ends that are produced each year. The shell (10) or (10 ') also minimizes the modifications that are required in the machining that exists in the field to form the crown (70) or (70') of double seam. That is, the only modification that is required in the machining to form the double stitched crown, is the replacement of a conventional or standard double seam mandrel with a new mandrel having the tronconical coupling surface (62) and the surface (68). ) generally cylindrical in the portion (64) of the bottom, which extends inside the flared and meshes the outer wall of the flared. Conventional double seam chucks typically have the slightly tapered surface 58, which extends at an angle of about 4o with respect to the central axis of the double seam chuck.

'While the can shell and can end shapes described herein, and that the method for forming the shell and the can end constitute preferable embodiments of the invention, it should be understood that the invention is not limited to those precise shapes. of tin shell and can end, and that changes can be made therein without departing from the competence and spirit of the invention, as defined in the appended claims.

What is claimed is:

Claims

1. A metal sheet tin shell having a vertical central axis and a curled peripheral crown adapted to be stitched double to a portion of the end of a can body formed of sheet metal, the shell comprising a central circular panel connected through of a curved wall. of the panel with an inner wall of a flare having a U-shaped cross section and an outer wall, a truncated mandrel wall having a portion of the wall extending at an angle greater than 16 ° relative to the central axis and connected to the outer wall of the flared in a first joint, the crown having an inner wall. connected to the mandrel wall in a second joint, the flare having a radius of curvature substantially smaller than a radius of curvature of the curved wall of the panel, the first joint being spaced below the level of the central panel, with a vertical distance between the first union and the second union, being greater than the width of the flaring at the bottom of the flaring, between the interior walls; and outside of the flaring, and the radius of curvature of the curved panel wall being greater than the width of the flaring. A shell as defined in claim 1, wherein the difference in diameters between the inner wall of the crown: and the outer wall of the flared is substantially greater than the radius of curvature of the flared. A shell as defined in claim 1, wherein the wall portion of the truncated mandrel wall extends at an angle between 25 ° and 30 ° with respect to the central axis. A shell as defined in claim 1, wherein the shell has a general height between the crown and the flaring of between .195 of an inch and .265 of an inch. A shell as defined in claim 1, wherein the flared has a generally flat bottom wall and curved inner and outer corner walls, which connects the bottom wall with the inner and outer walls of the flare, and each one of the corner walls has a radius of curvature less than a radial width of the bottom wall. A shell as defined in claim 1, in combination with a double seam mandrel having a common axis of rotation with the central axis of the shell, the seaming mandrel including an annular portion projecting inside the flare and having an outer surface engaging with the outer wall of the flaring, the seaming mandrel having a truncated surface engaging with the mandrel wall, and the seaming mandrel having a surface that meshes with the inner wall of the crown. 7. A shell, of sheet metal can having a vertical central axis and a curled peripheral crown, adapted to be double stitched with an end portion of a body of. tin formed of sheet metal, the shell comprising a. central circular panel connected through a curved panel with an inner wall of a flaring having an outer wall and a cross-section configuration in the form of ü, a generally truncated mandrel wall extending from the outer wall of the flaring, and having an inclined portion of the upper wall extending at an angle of at least 16 ° relative to the central axis, the mandrel wall having an inclined portion of the lower wall connected to the exterior wall of the flaring, in a junction disposed substantially below the level of the central panel, the crown having an inner wall connected to the upper portion of the wall of the mandrel wall, the "flaring" having a radius of curvature substantially smaller than a radius of curvature of the curved wall of the panel, and the width of the flaring being at the bottom of the flaring, between the inner and outer walls of the flaring, smaller than the radius of the flaring curvature of the panel wall and less than .040 of an inch. 8. A shell as defined in claim 7, in which the difference in diameters between the inner wall of the crown and the outer wall of the flaring is greater than the width of the flaring. A shell as defined in claim 7, wherein the upper portion of the wall of the mandrel wall extends at an angle of at least 25 ° relative to the central axis. A shell as defined in claim 7, wherein a short portion of a generally vertical rising wall connects the upper and lower wall portions of the mandrel wall. A shell 1 as defined in claim 7, wherein the inclined portion of the lower wall of the mandrel wall extends at an angle less than the angle of the portion of the upper wall, relative to the central axis . A shell as defined in claim 7, wherein the angle 'of the inner wall of the flare is inclined' at an angle between an angle of the inclined portion of the lower wall of the mandrel wall, and the angle of the inclined portion of the upper wall of the mandrel wall. A shell as defined in claim 7, wherein the mandrel wall connects to the inner wall of the crown at a first junction, and connects to the outer wall of the flaring at a second joint, and the axial distance between the first and second joints is substantially greater than the width of the flare.