This invention relates to the construction or forming of a sheet metal or aluminum can shell and can end having a peripheral rim or crown which is double-seamed to the upper edge portion of a sheet metal or aluminum can body. Such a can end is formed from a drawn sheet metal can shell, for example, a shell produced by tooling as disclosed in applicant's U.S. Pat. No. 5,857,374 the disclosure of which is herein incorporated by reference. Commonly, the formed can shell includes a circular center panel which extends to a panel wall which extends to or also forms the inner wall of a reinforcing rib or countersink having a U-shaped cross-sectional configuration. The countersink is connected by a generally frusto-conical chuckwall to an annular crown which is formed with a peripheral curl. For beverage containers, the center panel of the shell is commonly provided with an E-Z open tab, and after the can body is filled with a beverage, the peripherally curled crown of the shell is double-seamed to the upper end portion of the can body.
When the can body is filled with a carbonated beverage or a beverage which must be pasteurized at a high temperature, it is essential for the can end to have a substantial buckle strength to withstand the pressurized beverage, for example, a buckle strength of at least 90 psi. Such resistance to “buckle” pressure and “rock” pressure is described in detail in U.S. Pat. No. 4,448,322, the disclosure of which is incorporated by reference. It is also desirable to minimize the weight of sheet metal or aluminum within the can end without reducing the buckle strength. This is accomplished by either reducing the thickness or gage of the flat sheet metal from which the can shell is drawn and formed and/or by reducing the diameter of the circular blank cut from the sheet metal to form the can shell.
There have been many sheet metal shells and can ends constructed or proposed for increasing the buckle strength of the can end and/or reducing the weight of sheet metal within the can end without reducing the buckle strength. For example, U.S. Pat. No. 3,843,014, No. 4,031,837, No. 4,093,102, 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, No. 6,102,243, No. 6,460,723 and No. 6,499,622 disclose various forms and configurations of can shells and can ends and the various dimensions and configurations which have been proposed or used for increasing the buckle strength of a can end and/or reducing the metal in the can end. Also, published PCT application No. WO 98/34743 discloses a modification of the can shell and can end disclosed in above-mentioned U.S. Pat. No. 6,065,634. In addition to increasing the buckle strength/weight ratio of a can end, it is desirable to form the can shell so that there is minimal modifications required to the extensive tooling existing in the field for adding the E-Z open tabs to the can shells and for double-seaming the can shells to the can bodies. While some of the can shells and can ends disclosed in the above patents provide some of desirable structural features, none of the patents provide all of the features.
The present invention is directed to an improved sheet metal shell and can end and a method of forming the can end which provides the desirable features and advantages mentioned above, including a significant reduction in the blank diameter for forming a can shell and a significant increase in strength/weight ratio of the resulting can end. A can shell and can end formed in accordance with the invention not only increases the buckle strength of the can end but also minimizes the changes or modifications in the existing tooling for adding E-Z open tabs to the can shells and for double-seaming the can shells to the can bodies.
In accordance with one embodiment of the invention, the can shell and can end are formed with an overall height between the crown and the countersink of less than 0.240 inch and preferably less than 0.230 inch, and the countersink has a generally cylindrical outer wall and an inner wall connected to a curved panel wall. A generally frusto-conical chuckwall extends from the outer wall of the countersink to the inner wall of the crown and has an upper wall portion extending at an angle of at least 16° relative to the center axis of the shell, and preferably between 25° and 30°. The countersink may have a generally flat bottom wall or inclined inner wall which connects with the countersink outer wall with a small radius substantially less than the radial width of the bottom wall, and the inside width of the countersink at its bottom is less than the radius of the panel wall.
In accordance with modifications of the invention, a can shell and can end have some of the above structure and with the junction of a lower wall portion of the chuckwall and the outer countersink wall being substantially below the center panel. The lower wall portion of the countersink extends at an angle less than the angle of the upper wall portion relative to the center axis and is connected to the upper wall portion by a short wall portion which provides the chuckwall with a break or kick or a slight S-curved configuration. The countersink has a radius of curvature substantially smaller than the radius of curvature or radial width of the panel wall, and the inner bottom width of the countersink is also less than the radius or radial width of the panel wall, and preferably less than 0.035 inch. In a preferred embodiment, the countersink has an inclined bottom wall portion, and the panel wall has an inclined flat wall portion.
U.S. Pat. No. 7,341,163, which relates to a can shell and double-seamed can end, is hereby incorporated by reference in its entirety.
Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
The curved panel wall 16 with the radius R4 extends from an inner wall 17 of a reinforcing rib or countersink 18 having a U-shaped cross-sectional configuration and including a flat annular bottom wall 22 and a generally cylindrical outer wall 24 having an inner diameter D2, for example, of about 1.957 inches. The flat bottom wall 22 of the countersink 18 is connected to the inner panel wall 16 and the outer countersink wall 24 by curved corner walls 26 each having an inner radius R5 of about 0.010 inch. The radial width W of the flat bottom wall 22 is preferably about 0.022 inch so that the inner bottom width W1 of the countersink 18 is about 0.042 inch.
The outer wall 24 of the countersink 18 connects with a generally frusto-conical chuckwall 32 by a curved wall 34 having a radius R6 of about 0.054 inch. The chuckwall 32 extends at an angle A1 of at least 16° with respect to the center axis 11 or a vertical reference line 36 which is parallel to the center axis 11 of the shell. Preferably, the angle A1 is between 25° and 30° and on the order of 29°. The upper end of the chuckwall 32 connects with the bottom of a curved inner wall 38 of a rounded crown 42 having a curled outer wall 44. Preferably, the inner wall 38 of the crown 42 has a radius R7 of about 0.070 inch, the inner diameter D3 at the bottom of the curved inner wall 38 is about 2.039 inch, and the outer diameter D4 of the curled outer wall 44 is about 2.340 inches. The height C of the curled outer wall 44 is within the range of 0.075 inch and 0.095 inch and is preferably about 0.079 inch. The depth D from the bottom of the outer curled wall 44 or the junction 46 of the chuckwall 32 and the inner crown wall 38 to the inner surface of the countersink bottom wall 22 is within the range between 0.108 inch and 0.148 inch, and preferably about 0.126 inch. The junction 47 or the center point for the radius R6 has a depth G of about 0.079 from the junction 46 or bottom of the curled outer wall 44 of the crown 42.
As apparent from
The inner wall 38′ of the crown 42′ connects with the upper chuckwall portion 32′ at a junction 46′, and the outer wall 24′ of the countersink 18′ connects with the lower chuckwall portion 34′ at a junction 47′. The vertical height G1 from the bottom of the countersink 18′ to the kick or riser portion 35′ is about 0.086. The radius R10 is about 0.051 inch, and the lower wall portion 34′ extends at an angle A3 of about 15°. The countersink 18′ has a radius R9 of about 0.009 to 0.011 inch. Other approximate dimensions and angles for the shell 10′ shown in
The particular cross-sectional configuration of the can shell 10′ has been found to provide 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 chuckwall upper wall portion 32′ having an angle A2 relative to the center axis of at least 16° and preferably within the range of 25° to 30°. The lower wall portion 34′ of the chuckwall forms an angle A3 which is about 15°. The inner wall 38′ of the crown 42 forms an angle A4 preferably within the range of 5° to 30° and preferably about 16°. The inner wall 17′ of the countersink 18′ forms an angle A6 which is greater than 10° and about 13°. The width W1 of the countersink at the bottom between the inner wall 17′ and the outer wall 24′ is less than 0.040 inch and preferably about 0.024 inch. The radius R8 of the curved inner panel wall 16′ is substantially greater than the width W1 of the countersink 18′ and is about 0.049 inch.
The crown 42′ of the shell 10′ has a height C1 within the range of 0.075 inch to 0.095 inch and preferably about 0.082 inch and a height C2 within the range of 0.120 inch and 0.170 inch and preferably about 0.153 inch. The overall diameter D8 of the shell 10′ is about 2.337 inch, and the diameter D7 to the junction 46′ is about 2.036 inch. The inner bottom diameter D6 of the outer countersink wall 24′ is about 1.910 inch, and the difference W2 between D7 and D6 is greater than the countersink width W1, or about 0.063 inch. The diameter D9 for the center of the radius R8 is about 1.731 inch. It is understood that if a different diameter shell is desired, the diameters D6-D9 vary proportionately. The height H5 of the center panel 12′ above the bottom of the countersink 18′ is within the range of 0.070 inch and 0.110 inch and preferably about 0.078 inch. The height H6 of the shell 10′ between the top of the center panel 12′ and the top of the crown 42′, is within the range of 0.125 inch and 0.185 inch, and preferably about 0.149 inch.
Referring to
The wall portions 32″ and 34″ are connected by a kick or generally vertical or generally cylindrical short riser wall portion 35″ having relatively sharp inside and outside radii, for example, on the order of 0.020 inch. The upper chuckwall portion 32″ is connected to an inner wall 38″ of a crown 42″ having a curved outer wall 44″. As shown in
The inner wall 38″ of the crown 42″ connects with the upper chuckwall portion 32″ at a junction 46″, and the outer wall 24″ of the countersink 18″ connects with the lower chuckwall portion 34″ at a junction 47″. The vertical height G1 from the bottom of the countersink 18″ to the kick or riser wall portion 35″ is about 0.099. The radius R10 is about 0.100 inch, and the lower wall portion 34″ extends at an angle A3 of about 15°. The countersink 18″ has an inner radius R9 of about 0.021 inch and an outer radius R11 of about 0.016 inch. Other approximate dimensions and angles for the shell 10″ shown in
The particular cross-sectional configuration of the can shell 10″ has been found to provide performance results somewhat superior to the performance results provided by the can shell 10′. Accordingly, the details of the configuration of the can shell 10″ include a chuckwall upper wall portion 32″ having an angle A2 relative to the center axis of at least 16° and preferably within the range of 25° to 30°. The lower wall portion 34″ of the chuckwall forms an angle A3 which is about 15°. The inner wall 17″ of the countersink 18″ forms an angle A6 which is less than 10° and about 8°. The width W1 of the countersink at the bottom between the inner wall 17″ and the outer wall 24″ is less than 0.040 inch and preferably about 0.030 inch. The radius R8 of the curved inner panel wall 16″ is substantially greater than the width W1 of the countersink 18″ and is about 0.051 inch.
The crown 42″ of the shell 10″ has a height C3 from the bottom of the countersink 18″ of about 0.249 inch. The overall diameter D8 of the shell 10″ is about 2.336 inch. The inner bottom diameter D6 of the outer countersink wall 24″ is about 1.900 inch, and the difference in diameter W2 is greater than the countersink width W1, or about 0.047 inch. The diameter D9 for the center of the radius R8 is about 1.722 inch. It is understood that if a different diameter shell is desired, the diameters D6, D8 & D9 vary proportionately. The height H5 of the center panel 12″ above the bottom of the countersink 18″ is preferably about 0.081 inch. As shown in
The wall portions 132 and 134 are integrally connected by a curved portion 135 resulting in an angular break or a slightly reverse curve configuration formed by radii R10, R12 and R13. The upper chuckwall portion 132 is connected to an inner wall portion 138 of a crown 142 having a curved outer wall 144. The inner wall 138 of the crown 142 connects with the upper chuckwall portion 132 at a first junction 146, and the outer wall portion 124 of the countersink 118 connects with the lower chuckwall portion 134 at a second junction 147.
The approximate preferred dimensions and angles for the shell 110 shown in
The cross-sectional configuration of the can shell 110 having the above dimensions and angles has been found to provide performance results slightly superior to the performance results provided by the can shell 10′ and 10″. The added benefit of the angular or inclined inner countersink wall 117 is set forth in above mentioned U.S. Pat. No. 5,685,189, the disclosure of which is incorporated by reference. In addition, the combination of the beveled panel wall 116 and the inclined inner countersink wall 117 provide for increased buckle strength. Also, the above statements and advantages of the can shell 10′ and 10″ also apply to the can shell 110 shown in
The chuckwall portions 232 and 234 are integrally connected by a short wall portion 235 forming a kick or break between the upper and lower chuckwall portions 232 and 234 and formed by radius R10. The upper chuckwall portion 232 is connected to an inner wall portion 238 of a crown 242 having a curved outer wall 244. The inner wall 238 of the crown 242 extends at an angle less than 16° and connects by a radius R15 with the upper chuckwall portion 232 at a junction 246. As apparent from
The approximate and preferred dimensions and angles for the shell 210 shown in
The cross-sectional configuration of the can shell 210 having the above approximate dimensions and angles has been found to provide performance results somewhat superior to the performance results provided by the can shells 10′, 10″ and 110. The inclined or beveled panel wall 216 cooperates with the inclined inner wall 217 of the countersink 218 and the relative small radius R11 to increase buckle strength, and the inclined walls 224 and 234 and break-forming wall portion 235 cooperate to increase strength and prevent leaking during a drop test. The curved panel wall 116 (
By forming a shell and can end with the profile or configuration and dimension described above, and especially the profile of the bevel panel wall 216, countersink 218 and wall portion 234 shown in
The shell of the invention also minimizes the modifications required in the tooling existing in the field for forming the double-seamed crown 70 or 70′ or for double-seaming the crown 42″ or 142 or 242. That is, the only required modification in the tooling for forming the double-seamed crown is the replacement of a conventional or standard double-seaming chuck with a new chuck having the frusto-conical or mating surface 62 (
As appreciated by one skilled in the art, the end closures or shells described herein in
While the forms of can shell and can end herein described and the method of forming the shell and can end constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of can shell and can end, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.
This application is a Continuation of U.S. patent application Ser. No. 13/682,260, filed Nov. 20, 2012, now U.S. Pat. No. 8,931,660, which is a Continuation of U.S. patent application Ser. No. 12/904,532, filed Oct. 14, 2010, now U.S. Pat. No. 8,313,004, which is a Continuation of Ser. No. 10/936,834, filed Sep. 9, 2004, now U.S. Pat. No. 7,819,275, which is a Continuation-In-Part of abandoned U.S. patent application Ser. No. 10/361,245, filed Feb. 10, 2003, which is a Continuation-In-Part of U.S. patent application Ser. No. 10/078,152, filed Feb. 19, 2002, now U.S. Pat. No. 6,516,968, which is a Continuation-In-Part of U.S. patent application Ser. No. 09/898,802, filed Jul. 3, 2001, now U.S. Pat. No. 6,419,110, the entire disclosures of which are incorporated by reference herein.
Number | Date | Country | |
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Parent | 13682260 | Nov 2012 | US |
Child | 14593914 | US | |
Parent | 12904532 | Oct 2010 | US |
Child | 13682260 | US | |
Parent | 10936834 | Sep 2004 | US |
Child | 12904532 | US |
Number | Date | Country | |
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Parent | 10361245 | Feb 2003 | US |
Child | 10936834 | US | |
Parent | 10078152 | Feb 2002 | US |
Child | 10361245 | US | |
Parent | 09898802 | Jul 2001 | US |
Child | 10078152 | US |