Articulated tab opener for container

Abstract

A pull tab opener for a container having a push-in closure is articulated at a crease line behind the rivet connecting the tab to the container top surface. At least one protrusion extends upwardly from the base of the tab so that, when the rear lever portion is articulated about the crease line, to an amount at least in the range of 110° to 160°, and interference between the at least one protrusion and a cooperating face portion occurs, and the push-in closure is opened. There may also be cooperating protrusions. Another embodiment provides an undercut notch at each end of the crease line in the tubular peripheral edge of the pull tab opener.

We claim:  
     
         1 . A container and pull tab opener therefor; where said container has a top surface having a frangible push-in closure therein which is partially severable from said top surface, and where said pull tab opener is secured to said top surface near said frangible push-in closure; 
 wherein said pull tab opener comprises a nose portion and a tail portion;    wherein at least a portion of said nose portion overlies at least a portion of said frangible push-in closure; and    wherein said pull tab opener is secured to said top surface at a position on said pull tab opener which is between said nose portion and said tail portion;    said tail portion being articulable, and having a front lever portion which lies in the same plane and is an extension of said nose portion, and a rear lift lever portion which is articulably joined to said front lever portion at a crease line;    said tail portion comprising a base portion having a peripheral edge that is formed to so as to have a tubular configuration which extends above said base portion;    a pair of notches being formed in said tubular peripheral edge, wherein each notch extends upwardly from above said crease line at each end thereof, in a direction away from said nose portion;    wherein the height of said tubular peripheral edge at the bottom of each respective notch in the region of said crease line, and in a direction away from said nose portion, is reduced with respect to the remainder of said tubular peripheral edge;    wherein each said notch has an undercut notch defining face which extends upwardly from said reduced height portion of said tubular peripheral edge in a direction away from said nose portion, and which overlies said reduced height portion of said tubular peripheral edge and is spaced upwardly therefrom; and    wherein the angle of each said undercut notch defining face is in the range of from 10° to 30° with respect to said reduced height portion of said tubular peripheral edge.    
     
     
         2 . The combination of  claim 1 , wherein the angle between each said undercut notch defining face and the respective reduced height portion of said tubular peripheral edge is in the range of 15° to 25°.  
     
     
         3 . The combination of  claim 1 , wherein said pull tab opener is secured to said top surface by a rivet placed near said frangible push-in closure; and 
 wherein said rivet is positioned between said nose position and said tail portion.    
     
     
         4 . The combination of  claim 1 , wherein the material of said base portion is stamped in the region of said crease line so as have a reduced thickness.  
     
     
         5 . A container and pull tab opener therefor; where said container has a top surface having a frangible push-in closure therein which is partially severable from said top surface, and where said pull tab opener is secured to said top surface near said frangible push-in closure; 
 wherein said pull tab opener comprises a nose portion and a tail portion;    wherein at least a portion of said nose portion overlies at least a portion of said frangible push-in closure; and    wherein said pull tab opener is secured to said top surface at a position on said pull tab opener which is between said nose portion and said tail portion;    said tail portion being articulable, and having a front lever portion which lies in the same plane and is an extension of said nose portion, and a rear lift lever portion which is articulably joined to said front lever portion at a crease line;    said tail portion comprising a base portion having at least one protrusion upstanding therefrom at at least one side of said crease line;    said at least one protrusion having a front face which is subtended and extends upwardly away from said crease line, and being rectangular in shape; and    a cooperating face portion in said base portion on the side of said crease line opposed to said at least one protrusion, and adapted to contact said front face of said at least one protrusion when said tail portion is articulated about said crease line;    wherein said contact between said front face of said at least one protrusion and said cooperating face is effected when said rear lift lever portion has been articulated about said crease line by an amount in the range of 110° to 160°.    
     
     
         6 . The combination of  claim 5 , wherein there is at least one protrusion at each side of said crease line, and said cooperating face is a front face of a second protrusion opposed to and facing said first protrusion.  
     
     
         7 . The combination of  claim 6 , wherein there is a pair of protrusions formed at each side of said crease line.  
     
     
         8 . The combination of  claim 6 , wherein the angles at which each front face extends upwardly away from said crease line at each side thereof are equal.  
     
     
         9 . The combination of  claim 5 , wherein a single protrusion is formed only at one side of said crease line.  
     
     
         10 . The combination of  claim 5 , wherein angle of articulation at which contact between said front face of said at least one protrusion and said cooperating face is effected in the range of 120° to 140°.  
     
     
         11 . The combination of  claim 5 , wherein said pull tab opener is secured to said top surface by a rivet placed near said frangible push-in closure; and 
 wherein said rivet is positioned between said nose position and said tail portion.    
     
     
         12 . The combination of  claim 5 , wherein the perimeter of said pull tab opener is formed so as to have a tubular configuration, which extends below said base portion except in the region at each end of said crease line.  
     
     
         13 . The combination of  claim 5 , wherein the perimeter of said pull tab opener is formed so as to have a tubular configuration, which extends above said base portion except in the region at each end of said crease line.  
     
     
         14 . The combination of  claim 5 , wherein the material of said base portion is stamped in the region of said crease line so as have a reduced thickness.  
     
     
         15 . The combination of  claim 5 , wherein an elastic memory of the material of said pull tab opener, in the region of said crease line, is such that when said rear lift lever portion is pivoted about said crease line so as to bring said the first face of said at least one protrusion and said cooperating face into contact one with the other, said elastic memory is overcome and said rear lift lever portion is articulated to a new rest position relative to said front lever portion.