Patent ID: 7272918

Claim:
In a vacuum packaging machine comprising a sealing station consisting of a lower tool, an upper tool having a downwardly-projecting lower perimetric rim, and a reciprocal heating tool operatively associated with said upper tool having downwardly-projecting heating means, said lower tool having an upwardly-projecting upper perimetric rim consisting of an outer section against which said downwardly-projecting lower perimetric rim of said of upper tool is loaded during the sealing process and an inner section against which at least a portion of said downwardly-projecting heating means of said heating tool is loaded during the heat-sealing operation, mounting means in said upwardly-projecting upper perimetric rim of said lower tool, and sealing gasket means having a perimetric shape corresponding to said upwardly-projecting upper perimetric rim of said lower tool and defining an inner perimetric portion and an outer perimetric portion and comprising rib means extending downwardly from the bottom surface thereof for reception in said mounting means of said upwardly-projecting upper perimetric rim of said lower tool for providing a vacuum seal when said lower and upper tools are brought into abutting operational contact with each other, said sealing gasket means being sandwiched between said upwardly-projecting upper perimetric rim of said lower tool and said downwardly-projecting lower perimetric rim of said upper tool and said downwardly-projecting heating means of said heating tool during said sealing operation, the improvement comprising: said sealing gasket means comprising a first perimetric section of a first durometer hardness, and second section of a second durometer hardness less than said first durometer hardness; said first perimetric section comprising said outer perimetric portion of said sealing gasket means against which said downwardly-projecting lower perimetric rim of said upper tool abuts, and said second section comprising said inner perimetric portion of said sealing gasket means against which said downwardly-projecting heating means of said heating tool abuts during the sealing process.