Double ribbed cover

Abstract

A unitary closure is used with a tubular container having an open end with a cylindrical connecting bead at the open end. The unitary closure comprises a planar circular wall defining a flat upper surface having a peripheral edge. A first concentric ring is radially outwardly of the peripheral edge defining a first upwardly opening valley. A second concentric ring is radially outwardly of the first concentric ring at an annular peak and defines a second upwardly opening valley having a generally planar bottom wall. Inner and outer concentric ribs extend downwardly from the planar bottom wall. A connecting flange is radially outwardly of the second concentric ring including a downwardly opening channel receivable on the cylindrical connecting bead to close the open end of the container. The closure has a substantially greater wall thickness radially outwardly of the peak than radially inwardly of the peak.

Dependencies are inferred from the claim text.