Tab with rivet-receiving area, method of formation, and tooling therefor

Abstract

A method for manipulating a piece of material for use as a tab in conjunction with a container. The method includes accessing piece of relatively thin, sheet-like material and forming a hole in the piece of material. The method further includes performing a wiping operation to deform material adjacent to the hole, and performing at least one coining operation to flatten the deformed material. After the at least one coining operation the piece of material has an area of increased thickness adjacent to the hole, and after the at least one coining operation the piece of material has a generally straight inner portion at least partially defining the hole, where the generally straight portion extends at least about 20% of a height of the hole.

What is claimed is: 
     
         1 . A method for manipulating a piece of material for use as a tab in conjunction with a container, the method comprising:
 accessing piece of relatively thin, sheet-like material;   forming a hole in the piece of material;   performing a wiping operation to deform material adjacent to the hole; and   performing at least one coining operation to flatten the deformed material, wherein after the at least one coining operation the piece of material has an area of increased thickness adjacent to the hole, and wherein after the at least one coining operation the piece of material has a generally straight inner portion at least partially defining the hole, the generally straight portion extending at least about 20% of a height of the hole.   
     
     
         2 . The method of  claim 1  wherein the generally straight inner portion is straight and linear, and extends at least about 33% of the height of the hole. 
     
     
         3 . The method of  claim 1  wherein the deformed material, after the wiping operation but before the at least one coining operation, has an inner radius of less than about 5/1000″. 
     
     
         4 . The method of  claim 1  wherein the area of increased thickness protrudes outwardly from a lower surface of the piece of material, and does not protrude outwardly from a top surface of the piece of material, with regard to a tab orientation when the tab is configured to be coupled to the container. 
     
     
         5 . The method of  claim 1  wherein the area of increased thickness has an upper curved portion and a lower curved portion with regard to a tab orientation when the tab is configured to be coupled to the container, and wherein an effective radius of the upper curved portion is less than an effective radius of the lower curved portion. 
     
     
         6 . The method of  claim 5  wherein upper curved portion and the lower curved portion are both located immediately adjacent to the generally straight inner portion, and wherein the effective radius of the upper curved portion is less than about 50% than the effective radius of the lower curved portion. 
     
     
         7 . The method of  claim 1  wherein the area of increased thickness has an upper curved portion, with regard to the tab orientation when the tab is configured to be coupled to the container, having an effective radius less than about 4/1000″. 
     
     
         8 . The method of  claim 1  wherein the area of increased thickness has a thickness between about 1% and about 30% greater than at least one of the thickness of the piece of material during the accessing step, or the thickness of the piece of material, after the at least one coining step, at locations adjacent to but spaced away from the area of increased thickness. 
     
     
         9 . The method of  claim 1  wherein the area of increased thickness has a thickness between about 9.1/1000″ and about 12/1000″, and wherein the piece of material at locations adjacent to but spaced away from the area of increased thickness has a thickness of between about 9/1000″ and about 9.5/1000″ and less than the thickness of the area of increased thickness. 
     
     
         10 . The method of  claim 1  wherein the at least one coining operation includes a first, a second and a third coining operation, and wherein each coining operation reduces a radius of an upper curved portion of the area of increased thickness and increases the height of the generally straight portion. 
     
     
         11 . The method of  claim 1  the generally straight portion oriented is generally perpendicular to at least one of an upper surface of the area of increased thickness or an upper surface of the piece of material, with regard to the tab orientation when the tab is configured to be coupled to the container. 
     
     
         12 . The method of  claim 1  wherein the area of increased thickness has a generally flat lower surface oriented generally perpendicular to the generally straight inner portion. 
     
     
         13 . The method of  claim 12  wherein the generally flat lower surface extends in a direction parallel to at least one of an upper surface of the area of increased thickness or an upper surface of the piece of material, a distance of at least about 33% of a thickness of the piece of material, and wherein the upper and lower surfaces are upper and lower with regard to a tab orientation when the tab is configured to be coupled to the container. 
     
     
         14 . The method of  claim 1  wherein the area of increased thickness extends about an entire perimeter of the hole, and wherein the hole is circular in top view. 
     
     
         15 . The method of  claim 1  wherein the piece of material is in the form of the tab, wherein the tab is generally oval in top view and includes a front portion and a back portion located at opposite end thereof, wherein the back portion includes an opening therein and the front portion includes an opening formed therein with a peninsula positioned therein, wherein the hole is formed in the peninsula, and wherein the tab includes a rolled portion about an outer perimeter thereof. 
     
     
         16 . The method of  claim 1  further comprising coupling the piece of material to an end cap made of a relatively thin metal material via a rivet extending through the hole and coupled to the end cap, wherein the end cap has a main score line formed therein and defining a flap area, and wherein after the coupling step the tab is pivotable relative to the rivet about an axis oriented in a direction parallel to a plane of the end cap such that a front portion of the tab is pressable into the flap area to cause the main score line to tear along its length. 
     
     
         17 . A system including a tab for use in connection with a container comprising:
 a generally oval tab body having a front portion and a back portion and made of a piece of relatively thin, sheet-like material; and   a hole positioned in the tab;   wherein the tab body includes an area of increased thickness adjacent to the hole, wherein the area of increased thickness has a generally straight inner portion extending at least about 20% of a height of the hole.   
     
     
         18 . The system of  claim 17  wherein the area of increased thickness has a thickness between about 1% and about 30% greater than a thickness of the tab body at areas adjacent to but spaced away from the area of increased thickness, wherein the tab body is generally oval in top view and includes a front portion and a back portion located at opposite end thereof, wherein the front portion includes an opening formed therein with a peninsula positioned therein and the back portion includes an opening therein, wherein the hole is formed in the peninsula, and wherein the tab body includes a rolled portion about an outer perimeter thereof. 
     
     
         19 . The system of  claim 17  further comprising an end cap made of a relatively thin metal material, wherein the tab is coupled to the end cap via a rivet extending through the hole and coupled to the end cap, wherein the end cap has a main score line formed therein and defining a flap area, and wherein the tab is pivotable relative to the rivet about an axis oriented in a direction parallel to a plane of the end cap such that a front portion of the tab is pressable into the flap area to cause the main score line to tear along its length. 
     
     
         20 . Tooling for forming a tab comprising:
 a piercing toolset including a male punch and a supporting female structure, wherein the male punch is configured to extend through a tab or tab precursor and be closely received in the supporting female structure to thereby remove a piece of material from the tab or tab precursor and form a hole in the tab or tab precursor;   a wiping toolset including a female wiping tool and a male wiping tool configured to be received in the female wiping tool to thereby form an area of deformed material of the tab or tab precursor positioned at or adjacent to an inner edge of the hole; and   a coining toolset including a male coining tool and a female coining tool configured to compress at least part of the tab or tab precursor therebetween in an axial direction to perform coining operations on the area of deformed material of the tab;   wherein at least one of: a) the male punch of the piercing toolset has a diameter less than 0.1260″; or b) the supporting female structure of the piercing toolset has a diameter less than 0.1282″; or c) the male wiping tool of the wiping toolset has a diameter greater than 0.1300″; or d) the male wiping tool has an upper inner corner positioned adjacent to the deformed material of the tab or tab precursor during wiping operations, having a radius less than 0.0050″; or e) the female wiping tool has an inner corner configured and positioned such that the deformed area of the tab or tab precursor is deformed about the inner corner during wiping operation, the inner corner of the female wiping tool having a radius of less than 0.0030″; or f) the female coining tool has a central opening receiving the male coining tool therein, the central opening having a diameter of less than 0.1310″; or g) the coining toolset has an upper inner corner positioned adjacent to the tab or tab precursor during coining operations, the upper inner corner having a radius less than 0.030″; or h) the male coining tool has an upper outer corner positioned adjacent to the tab or tab precursor during coining operations, the upper outer corner of the male coining tool having a radius less than 0.0050″.