Reclosable lid for a food or beverage container and having a vacuum or pressure release button

Abstract

A sheet metal lid has a rim portion removably secured to a container and includes a vent button having a top wall portion surrounded by a side wall portion and an outwardly projecting flange portion. A portion of the button has an arcuate shear line extending substantially into or through the sheet metal, and the sheet metal is flattened or compressed at the shear line to form positively connected opposing sheet metal portions. A resilient sealant material is bonded to the inner surface of the vent button, and the opposing sheet metal portions and the sealant material form a small gap for releasing a vacuum or pressure from the container in response to downward pressure on the top wall portion of the vent button.

What is claimed is: 
     
         1 . A sheet metal lid having a vertical axis and including a top wall and a peripheral rim portion adapted to be secured to a container receiving a product and having vacuum or pressure, the lid comprising
 a portion of the top wall defining a vent button having a top wall portion, a surrounding side wall portion with an outwardly projecting flange portion extending around the side wall portion,   a portion of the vent button having an arcuate shear line extending substantially into the thickness of the sheet metal forming the vent button,   the portion of the vent button having the shear line being compressed at the shear line to provide for obtaining a predetermined downward pressure required on the top wall portion of the vent button to separate opposing portions of the sheet metal at the shear line,   a resilient sealant material bonded to an inner surface of the vent button and having a portion overlapping the arcuate shear line, and   the portion of the sealant material being effective to form a narrow gap along the shear line in response to depressing the top wall portion of the vent button for releasing vacuum or pressure from the container.   
     
     
         2 . A lid as defined in  claim 1  wherein the shear line extends completely through the sheet metal and forms opposing portions for defining the gap, and the opposing portions of the sheet metal being axially compressed to be substantially flush with the sheet metal adjacent the shear line. 
     
     
         3 . A lid as defined in  claim 1  wherein the top wall portion of the vent button includes a generally triangular and downwardly projecting recess portion for indicating where to depress the top wall portion to separate the opposing portions and produce the gap. 
     
     
         4 . A lid as defined in  claim 1  wherein the top wall portion of the vent button is below the top wall of the lid before pressure is applied to the top wall portion of the vent button. 
     
     
         5 . A lid as defined in  claim 1  and including a circular bead in the flange portion of the vent button. 
     
     
         6 . A sheet metal lid having a vertical axis and including a top wall and a peripheral rim portion with a bonded sealant material, and adapted to be releasably secured to a container receiving a vacuum or pressure enclosed product, the lid comprising,
 a portion of the top wall defining a vent button having a top wall portion, a surrounding side wall portion with an outwardly projecting flange portion extending around the side wall portion,   the flange portion having an arcuate shear line projecting into the flange portion adjacent the side wall portion of the button and extending substantially through the thickness of the sheet metal forming the flange portion,   an arcuate bead within the flange portion and disposed laterally outwardly from the arcuate shear line,   the flange portion being axially compressed at the shear line to obtain a predetermined downward pressure required on the top wall portion of the vent button to separate opposing flange portions of the sheet metal at the shear line,   a resilient sealant material bonded to an inner surface of the vent button and having a portion projecting laterally outwardly onto an inner surface of the lid and overlapping the shear line, and   the projecting flange portion of the sealant material being effective to define a narrow gap along the shear line in response to depressing the top wall portion of the vent button for releasing vacuum or pressure from the container.   
     
     
         7 . A lid as defined in  claim 6  wherein the opposing flange portions of the sheet metal at the shear line cooperate to define the gap, and the opposing flange portions of the sheet metal being axially compressed to be substantially flush with the sheet metal forming the flange portion at the shear line. 
     
     
         8 . A lid as defined in  claim 6  wherein the top wall portion of the vent button includes a generally triangular and downwardly projecting recess portion for indicating where to depress the top wall portion to separate the opposing flange portions and produce the gap. 
     
     
         9 . A lid as defined in  claim 6  wherein the top wall portion of the vent button is below the top wall of the lid before pressure is applied to the top wall portion of the vent button. 
     
     
         10 . A lid as defined in  claim 6  wherein the bead is circular. 
     
     
         11 . A method of adding a vacuum or pressure release button to a sheet metal lid having a vertical axis and a peripheral rim portion adapted to be secured to the top end portion of a container for a product and having a vacuum or gas pressure, the method comprising the steps of
 pressing a portion of the top wall of the lid downwardly to form an upwardly projecting vent button,   forming the vent button with a top wall portion and a surrounding side wall portion extending to a flange portion projecting laterally outwardly from the side wall portion,   forming a downwardly projecting bead within the flange portion adjacent the side wall portion of the vent button,   shearing an arcuate portion of the flange portion between the side wall portion and the retention bead to form an arcuate shear line extending substantially through the metal thickness of the flange portion,   compressing a top surface and a bottom surface of the flange portion along the shear line between opposing tooling members to select the downward force required on the top wall portion of the vent button to shear the sheet metal at the shear line, and   bonding a sealant material to an inner surface of the vent button below the shear line and effective to define a vacuum or pressure release gap in response to depressing the top wall of the vent button above the shear line for releasing vacuum or gas pressure from the container.   
     
     
         12 . A method as defined in  claim 11  wherein the step of shearing an arcuate portion of the flange portion comprises shearing completely through the sheet metal and separating opposing flange portions, and axially compressing the flange portions back together into opposing alignment. 
     
     
         13 . A method as defined in  claim 11  wherein the step of bonding the sealant material to the inner surface of the button is performed when a sealant material is bonded to the rim portion of the lid. 
     
     
         14 . A method as defined in  claim 11  and including the step of forming a generally triangular recess portion into the top wall portion of the vent button. 
     
     
         15 . A method of adding a vacuum release button to a sheet metal lid having a vertical axis and a horizontal peripheral rim portion adapted to be releasably secured to the open end portion of a container for a vacuum or gas pressure product, the method comprising the steps of
 pressing a portion of the top wall of the lid downwardly to form an upwardly projecting vent button,   forming the vent button with a top wall portion and a surrounding side wall portion extending to an annular flange portion projecting laterally outwardly from the side wall portion,   forming a downwardly projecting bead within the flange portion adjacent the side wall portion of the vent button,   shearing an arcuate portion of the flange portion between the side wall portion and the bead to form an arcuate shear line extending substantially into through the flange portion,   compressing a top surface and a bottom surface of the flange portion along the shear line between opposing tooling members to control the downward force required on the top wall portion of the vent button to shear the sheet metal at the shear line, and   bonding a sealant material to an inner surface of the vent button below the shear line and effective to define a vacuum or pressure release gap in response to depressing the top wall of the vent button above the shear line for releasing vacuum or gas pressure from the container.   
     
     
         16 . A method as defined in  claim 15  wherein the step of shearing an arcuate portion of the flange portion is effect to separate opposing flange portions, and axially compressing the flange portions back together into opposing alignment. 
     
     
         17 . A method as defined in  claim 15  wherein the step of bonding the sealant material to the inner surface of the button is performed when a sealant material is bonded to the rim portion of the lid. 
     
     
         18 . A method as defined in  claim 15  and including the step of forming a generally triangular recess portion into the top wall portion of the vent button. 
     
     
         19 . A method as defined in  claim 15  wherein the step of shearing an arcuate portion of the flange portion comprises shearing the sheet metal into the top and bottom sides of the flange portion.